Harvard expert shares the No. 1 lesson to learn from Warren Buffett’s career: 'You can't be really successful' without it

Warren Buffett holds a unique place in the hearts and minds of investors all over the world.

A key trait helped him reach such prestige, according to Harvard University leadership expert Bill George: Buffett, the longtime CEO of holding company Berkshire Hathaway, found the "sweet spot" between doing something he's good at and doing something he actually enjoys.

Achieving that balance makes leaning on your strengths and staying motivated over time easier, says George, a Harvard Business School executive fellow and ex-CEO of medical device company Medtronic.

"To be truly successful, to do anything great, you have to use your strengths,. You can't just correct your weaknesses," George tells CNBC Make It. Motivation is equally important, he adds: If your work "doesn't excite you, it just becomes a time attack."

"So I think you need both to be truly successful," he says. "You can get by on one, but you can't be really successful unless you have both."

George studied Buffett's leadership and Berkshire Hathaway's shareholder meetings ahead of co-writing his 2022 book, "True North: Emerging Leader Edition." Figuring out what drives you and what you have to offer the world is the first step to achieving Buffett's level of self awareness, George and co-author Zach Clayton wrote — but that's easier said than done. 

Here's how to tap into the same sweet spot Buffett found, says George.

There are two types of motivation, George says: extrinsic motivation, like a comfortable salary, and intrinsic motivation, like enjoying a job where you get to help people every day.

Both play a role in career longevity. "If you're just motivated by making a lot of money, it will run out on you. You'll find that things are very hollow and you don't actually