9 Things You Never Knew About PayPal's Peter Thiel

— -- PayPal founder Peter Thiel, 47, says the most difficult lesson to learn is to "think for yourself."

The billionaire-investor is widely known as one of the most disruptive thinkers on the planet. He’s famed for co-founding PayPal, was the first investor in Facebook and is now seeding some of the most successful startups today from LinkedIn, to Airbnb and Yelp.

Some of the top entrepreneurs in the world made their mark at PayPal and went off to create YouTube, Tesla and SpaceX.

In his new book, "Zero to One: Notes on Startups, or How to Build The future," Thiel emphasizes, “Great companies are one-of-a-kind” and he includes exercises to encourage people to think about the world in different ways.

In an interview with Rebecca Jarvis, ABC News’ chief business and economics correspondent, Thiel opened up about his own roller coaster ride and dealing with self-doubt while trying to start-up PayPal. “You think you’re going to take over the world, you think you’re all going to die, and sometimes you move back and forth several times a day,” said Thiel.

ABC News wanted to get to know the man behind these multi-billion dollar ideas, so we asked him about his favorite toy as a kid and worst childhood memory in Real Biz Rapid Fire.

Here are nine things you mostly likely don’t know about Peter Thiel

1. Favorite toy as a kid?Legos.

2.Worst memory as a kid.

“Crashing my bicycle, when I drove down the hill really fast.”

3. First memory as a kid.

“Getting a birthday present at age 3--it was a big square box, it was a globe of the world.”

4. What time do you wake up?

Thiel wakes up at 6:30 in the morning. And get this, he doesn’t set an alarm. Thiel wakes up on his own.

5. How much sleep does Thiel get?

Six to seven hours a night.

6. Most difficult lesson Thiel ever had to learn?

People change. Thiel said, “Sometimes, people that you’re great friends with, they often change over the years in ways that you don’t fully appreciate.”

7. Most difficult lesson to teach?

“It’s very hard to teach how to think for yourself because it’s almost paradoxical.”

8. Does Thiel listen to music online?

Yes. Thiel likes Spotify. And the last song he downloaded is from Swedish electronic musician and record producer Tim Bergling, known by his stage name Avicii.

9. Last thing Thiel bought online?

Hard-cover book from Amazon. “Capital in the Twenty-First Century” by Thomas Piketty.