Six weeks before co-founder and chairman Steve Jobs’s death in October 2011, Tim Cook was named Apple’s new Chief Executive Officer. At that time, the 50-year-old Cook had garnered a reputation for managerial doggedness, routinely holding hours-long meetings and expecting answers to emails sent round the clock.

As VP of Corporate Materials for Compaq, one of the mid-1990s’ largest PC retailers, Cook had been headhunted by a corporate recruiter in 1998 to serve as Apple’s Senior VP of worldwide operations within a retooled leadership team; Jobs had himself recently returned to Apple as interim CEO in the summer of 1997 following the company’s purchase of his floundering computer and software development enterprise, NeXT, Inc. Dell Computer founder Michael Dell remarked that, in view of the worst financial quarter in Apple history, were he in Jobs’s place, “I’d shut [Apple] down and give the money back to shareholders.”

Appearing at MacWorld the following spring, however, Jobs revealed that Apple had finally posted a profitable quarter, the turnaround due, in no small part, to Cook’s bold decision to replace Apple-owned factories and warehouses with contract producers; a background in supply-chain management later gave Cook an edge when brokering “backstage” deals on flash memory with manufacturers.

What, then, do we know of Tim Cook, an Apple CEO who, unlike his predecessor, isn’t especially known for generating media buzz through pioneering product launches?

15. Cook Initially Dismissed Apple’s Request for an Interview

When first contacted by executive headhunters in 1998 regarding a position at Apple, the then 37-year-old Cook was skeptical, to say the least; contributing editor for SUCCESS magazine Chris Raymond affirms that, according to Cook, most people said he was crazy for even thinking of leaving what was considered by most to be the world’s top PC company. Speaking to Charlie Rose in 2014, Cook revealed that he eventually consented to take the interview out of an eagerness to meet Jobs, the man who had “created the whole [computing] industry.” Later, upon first meeting Jobs one-on-one and discussing the as yet unreleased iMac, Cook had an epiphany: “I thought, ‘I’m doing it. I’m going for it.’ And you have this voice in your head that says, ‘go west, young man, go west.’” As Cook admitted to Rose, “I listened to my gut.”

14. Cook Rejects the Motto WWJD (“What Would JOBS Do”)

Since becoming CEO in 2011, Cook has often shared the advice that an ailing Jobs gave him shortly before his decision to step down; in an interview for Bloomberg Businessweek in 2012, Cook recounts how, during one of his final telephone conversations with the Apple co-founder, Jobs had told him to stop second-guessing himself. Jobs feared that what had happened to the Disney company following Walt’s death might likewise befall Apple in the wake of his own passing. He told Cook that, as Disney employees sat discussing “what Walt would have done,” the business became paralyzed; reflects Cook, “[Jobs] goes, ‘I never want you to ask what I would have done. Just do what’s right.’” Speaking exclusively to The Washington Post in 2016, Cook elaborated on his boss’s good counsel: “[Jobs] took away the self doubt that would naturally be there in whoever followed him. […] It took away the heavy weight.”

13. Cook is “The Strong, Silent Type”

While promoting her new book, Radical Candor: Be a Kickass Boss without Losing Your Humanity (2017), former Google and Apple employee Kim Scott recalls what it was like to interview with the enigmatic CEO: “[S]omebody warned me, ‘Tim is extremely quiet. Don’t let it unnerve you.’”

Unfortunately, when Cook asked her to reveal what she considered to be her biggest mistake at Google, Scott quickly realized that the advice had failed to make an adequate impression. “[B]ecause he was so quiet[,] I started confessing a little bit more about this mistake than I really needed to be telling a perfect stranger in an interview. […] I was about to tell him something that probably was going to cost me the job.” Luckily for Scott (and her job prospects!), the Apple HQ building in which she was being interviewed suddenly began to sway, prompting her to break off her confession and ask Cook what was happening; quips Scott, “I had been saved by the bell” (well, an earthquake, … actually).

12. “Curious Cook” Has Plenty of Questions

In her book, Haunted Empire: Apple After Steve Jobs (2014), former Wall Street Journal Apple reporter Yukari Iwatani Kane contends that while Cook values collaboration and teamwork, Apple’s CEO doesn’t pull any punches: weekly meetings can last as long as five or six hours if staff are unable to provide adequately detailed answers to Cook’s penetrating queries. Should any figure be wrong or missing, Cook has been known, for instance, to repeatedly put the same question to an employee ad nauseum (e.g., “Why is that?” and/or “Why are you not making it clear?”). Because such fearsome encounters are so frequent, Kane explains that attendees will often prepare for meetings as if they were cramming for a final exam. And, should someone completely fail to answer one of his myriad questions, Cook, writes Kane, will sit in silence while colleagues, shifting uncomfortably in their seats, stare at the table.

11. Cook Enjoys his Privacy

Within days of publicly “coming out” to readers of Bloomburg Businessweek in 2014, Cook spent his 54th birthday weekend in relative seclusion; on Saturday morning, he could be seen sporting nondescript sportswear as he went about purchasing a few groceries and having his car washed close to home. In his 800-word Businessweek essay, Cook admits that a desire to remain aloof throughout his professional life (“I come from humble roots, and [so] don’t seek to draw attention to myself”) had prevented him from “doing something more important”: “[I]f hearing that the CEO of Apple is gay can help someone struggling to come to terms with who he or she is, […] then it’s worth the trade-off with my own privacy.” Not surprisingly, Cook’s hobbies, which include hiking and mountain biking, also tend towards the solitary.

10. He Hobnobs in the Cafeteria

Characteristically introverted, Cook has traditionally avoided one-on-one interactions with staff, even choosing to steer clear of the company gym. Since becoming CEO, however, the media-shy mogul has been known to casually sit down with Apple employees at lunchtime. According to Fortune’s executive editor, Adam Lashinsky, Jobs often preferred to eat lunch with Apple’s design chief officer, Jonathan Ive. Former Apple employee David Black remembers that on the rare occasions that Jobs sat outside on the patio at lunch, coworkers would make short work of their meals. “[N]o one would fill the seats near him,” recalls Black, for fear of being asked what they were working on; “[i]t was just that little moment of being challenged.” While vacationing or otherwise out of the office, however, Cook routinely dines solo.

9. Cook is a VERY Early Bird

Like other top executives who rise well before the sun to take advantage of pre-workday solitude, Cook wakes up every morning at 3:45 a.m. After an hour spent emailing, he heads over to the gym; a quick visit to Starbucks is paid before Apple’s workaholic CEO finally makes it into the office. And while boasting about being the first to arrive and the last to leave, Cook routinely devours energy bars during meetings.

Speaking to The Wall Street Journal in 2016, psychologist Josh Davis argues that, “when you’re not concerned with people trying to get your attention, you’re dramatically more effective.” Author of Two Awesome Hours (2015), Davis suggests that when the temptation of responding to text messages, emails, and social media notifications is eliminated, one can approach obstacles in a more relaxed and thereby constructive frame of mind.

8. His Home is No Castle

Unlike billionaire Oracle co-founder and notorious “trophy-home buyer” Larry Ellison, Cook lives in a modest 2,400 square-foot home in Palo Alto, CA; he purchased the house for $1.9 million USD in 2010, a relatively small sum in the city’s hot housing market. Conversely, Jobs’s former abode, located little more than a mile away from Cook’s four-bedroom condo, boasts 7 bedrooms, 4.5 bathrooms, and over a half-acre of land. His parents, Donald and Geraldine Cook, though having become celebrities in Cook’s rural hometown of Robertsdale, Alabama, continued to live in the CEO’s humble childhood home. Asked to reflect on his choice of residence, Cook replied, “I like to be reminded of where I came from, and putting myself in modest surroundings helps me do that. Money is not a motivator for me.”

7. Cook is a HUGE Fan of Auburn Tigers’ Football and Duke Blue Devils’ Basketball

A graduate of both Auburn University (1982) and Duke University’s Fuqua School of Business (1988), Cook is proud to show school spirit; as his Twitter bio succinctly states, “CEO Apple, [f]an of Auburn football and Duke basketball.” Cook’s office and home are packed with school memorabilia. Delivering the 2010 Auburn commencement speech, he told attendees that he felt privileged to be back: “Auburn has played a key role in my life and continues to mean a lot to me.”

During the Blue Devils’ winning NCAA Final Four men’s basketball championship game in 2015, Cook made headlines when, while taking photos with fans, he was seen sporting an Apple Watch mere weeks before the device’s official release date. Later, while discussing the watch at Apple’s Spring Forward event, Cook demonstrated how users could get alerts on the device by checking the latest NCAA scores.

6. Though Twice Voted “Most Studious,” Cook wasn’t a “Nerd”

Speaking with AL.com urban issues’ reporter Mike Finch in 2014, former high school teachers and classmates remember Cook as a studious, lanky teenager, one who, recalls math teacher Barbara Davis, “was just the kind of person you liked to be around.” Reliable and meticulous in his work, Cook became the yearbook staff’s business manager in his senior year and played trombone in the school band. He and fellow top student Teresa Prochaska Huntsman (Cook would graduate second in the class), fearing that they weren’t “learning enough” in Chemistry class, petitioned their counselor to be placed in a more challenging course. Their concern was unwarranted; both students later studied industrial engineering at Auburn University.

(Conversely, an FBI background check released in 2012 reveals that Jobs earned mostly Bs and Cs; he graduated from high school in 1972 with a 2.65 GPA.)

5. Young Timothy Once Stumbled Upon a Cross Burning

Born to working class parents in rural Alabama at a time when the state’s African American citizens were still staging sit-ins to desegregate public libraries and lunch counters, Cook was no stranger to the most shameful expressions of racial prejudice. When still a boy, he had taken his brand-new 10-speed bicycle out for a ride when he first saw the flames and smelled smoke; men cloaked in white hoods and robes had set fire to a wooden cross on a neighbour’s front lawn. Upon shouting at the men to, “Stop!” a stupefied Cook witnessed one of the klansmen raise his hood; before speeding away, Cook recognized the man as a local church deacon. The Apple CEO, accepting a lifetime achievement award from Auburn University in December 2013, recalled the experience as one whose image had become, “permanently imprinted on my brain, and it would change my life forever.”

4. “Crusading Cook” Speaks Out Against Discriminatory Laws

When the Indiana state legislature passed a controversial bill in early 2015 that effectively gave business owners the right to turn away gay, lesbian, and transgender patrons on the basis of “religious freedom,” Cook wrote an editorial for the Washington Post. Cook, who had himself only recently declared that he was “proud to be gay” in a lengthy Bloomberg Businessweek editorial the previous autumn, observed that such laws, “rationalize injustice by pretending to defend something many of us hold dear.” In a related tweet, the Apple CEO admitted that he was, “deeply disappointed in [the] new law”; “[a]round the world,” writes Cook, ”[Apple] strive[s] to treat every customer the same — regardless of where they come from, how they worship, or who they love.”

3. Cook Could Go to Jail

In the wake of what appears to be Apple’s unwillingness to assist law enforcement in unlocking an iPhone 5 belonging to one of the 2015 San Bernardino terror attack suspects, some experts believe that Cook could face jail time. In February 2016, the FBI obtained a federal court order under a 1789 law requiring Apple to create a version of iOS 9 (nicknamed “GovtOS”) that would enable investigators to try multiple pass codes (i.e., the phone would otherwise erase itself after 10 wrong guesses); should Apple fail to comply, Cook might be held in contempt of court. Writing for TIME magazine, Lev Grossman notes that Cook takes pride in positioning Apple as a defender of customer privacy, a company whose profit margins don’t rely on mining users’ data. Cook clarified his position in an email sent to staff, stating that the order, “threatens everyone’s civil liberties.”

2. “Kindly Cook” has Promised to Give Away his Entire Fortune

Speaking with Fortune’s executive editor, Adam Lashinsky, in 2015, Cook disclosed that he had quietly begun donating money to various causes and that he planned to dispense with simply “writing cheques” by developing a more systematic approach to philanthropy. Once he has funded his nephew’s college education, Cook plans to give away his entire fortune, estimated to be worth some US$785 million (2015).

Cook has also taken decidedly public positions on a number of global issues, including immigration reform, preventing the transmission of AIDS, and human rights. Observes Cook, “[y]ou want to be the pebble in the pond that creates the ripple for change.” According to Fortune’s Lashinsky, changing the world has always been more important to Cook than making money.

1. Cook Wanted to Give Jobs Part of his Liver

In the 2015 biography Becoming Steve Jobs, technology writer Brent Schlender and Fast Company’s Rick Tetzeli reveal that in 2009, a distraught Cook decided to have his blood tested in hopes that he might, in some way, be able to slow the steady decline of Jobs’s health. Realizing that both men’s rare blood types were likely a match, Cook underwent a series of tests to determine whether a partial liver donation was even possible; as the liver is a regenerative organ, only a portion need be transferred. When Cook visited his employer’s home to propose the transplant, Jobs, recalls Cook, “cut me off at the legs, almost before the words were out of my mouth.” In what, according to Cook, was one of the four or five times that Jobs ever yelled at him, the ailing Apple co-founder exclaimed, “No, I’ll never let you do that. I’ll never do that.”

Sources: uk.businessinsider.com, money.cnn.com, washintonpost.com, cnbc.com, theatlantic.com