? From billionaire Bill Gates to former Meta exec Sheryl Sandberg, the world’s top performers all have one thing in common: They invest in their own potential, says Bill Hoogterp, the Fortune 500 career coach who’s worked with both. He recalls Gates blocking off an entire week to read in a cabin. “More and more leaders are doing the same thing,” he exclusively tells Fortune—and the sooner Gen Z copies them, the better for their careers.

Bill Hoogterp has spent decades advising celebrities, CEOs, and rising stars inside some of America’s most powerful boardrooms. Through his coaching firm, LifeHikes, he’s helped more than 700,000 professionals level up their communication and leadership skills—and personally worked one-on-one with “thousands” of executives, many of whom appear on Fortune’s most powerful lists.

And there’s one habit that Meta’s former chief operating officer, Sheryl Sandberg, and his top power player clients share.

“I had this chat with Sheryl Sandberg, and we were joking around that we all need to be the CEO of our own potential,” Hoogterp tells Fortune.

The problem? “Almost none of us seems to want the job. We’re constantly kind of deferring to what the world wants and just reacting to everybody else.”

But what the top 1% do well, Hoogterp says, is they invest in themselves—and it’s something he says everyone should be doing if they want to elevate their careers. Especially Gen Zers, who are early in their careers and stand to gain the most by consistently backing their own growth.

“So think of it like this: You have a pot of money, a few $1,000, and you’re starting your career. You could sit it, put it under the mattress and pick it up, 30 to 60 years later,” he explains. “Or you can invest it in the bank and get interest on it every year. Which one would you rather do?”

Hoogterp says to imagine the return you’d expect from an investment—say 10%—and commit that percentage of your time to improving yourself each week.

“So if you are putting in 40 to 50 hours a week, that’s going to be about five hours,” Hoogterp explains. “Every week, you’re going to spend four or five hours on you. Now, whether that’s going to trainings, getting coaching, reading books, watching TED talks, it doesn’t matter. But take it seriously.”

“If you do that every week, your thousands of dollars are going to be worth tens of millions of dollars, whereas somebody else is going to wake up—they’re just as smart, they’re just as good people as us—but 20 years goes by, and they’re more or less in the same position, same mindsets, same place.”

“That interest compounded is based on you, investing in you.”

Books: Bill Gates’ way of investing in himself

If you don’t know where or how to start investing in yourself, Hoogterp suggests taking up reading.

“The top leaders in the world spend an hour a day reading,” he says, adding that they often start their day in the early hours of the morning with a book in their hands. But it doesn’t have to be a daily chore.

“I spent a little time with Bill Gates, and he found that there were a lot of books and articles, things he wanted to read and just didn’t have time,” he adds. “We all have that stack on our nightstand of books that we want to read but haven’t had time.”

So what did the billionaire Microsoft co-founder do? “He took a whole week, blocked everything off, went to a cabin and just read books. He said it was transformative to his life… In fact, Bill now does two weeks a year just reading.”

“More and more leaders are doing the same thing,” Hoogterp adds. “So finding time to really, just really go off the grid, give yourself time to think, but with a purpose—get through that stack of books you’ve been meaning to get to, or TED talks or articles, or a little bit of both.”

“And that is another way to think about how seriously the most successful people take their own learning and growth, whereas us less successful people, we’re just running through the motions. We’re trying to catch up.”

But I am not a reader, what can I do?

Unfortunately for those who prefer to watch videos rather than pick up a book, Hoogterp says reading really is the key here.

“You’ve got to give yourself a disparate diet for your mind,” he explains. “So you do want a mix of reading, whether it’s long form, books, or articles. Podcasts are great, but try to mix it up.”

“Reading is different because you retain almost 31% more when you read something than when you listen to it on audiobooks, because you’re actively processing versus passively processing.”

“And get the pen out, like when you were back in school writing notes in the margin of the book because you think it might be on the test. Oh, this makes me think this,” Hoogterp adds. “Your brain remembers you writing the words, which means you’re actively processing much deeper, much faster, much more powerfully.”

Finally, if you still can’t get the mojo to park some time aside and read, Hoogterp suggests joining a book club. Not only will it hold you accountable, but it’ll force you to dig deeper, ask better questions, and walk away with ideas you can actually use.

“You’re not just reading a book with other people, but you’re tackling it together,” he says. “What do you think about this chapter? Oh, that made me think this. I agreed with this. I didn’t agree with that.”