What do you get the world's richest person for his birthday?
That's the question Bill Gates' friends and family pondered as the Microsoft co-founder turned 59 years old Tuesday.
Gates, who stepped down from the top job at Microsoft six years ago, is now worth $81.2 billion, according to Forbes, leading Mexican telecom tycoon Carlos Slim by a mere $2 billion.
But how much do you really know about the tech pioneer and philanthropist?
While it may be difficult to help Gates' loved ones choose a gift that he doesn't already have, we have you covered.
1. HE HAS NO INTEREST IN BEING WORLD'S RICHEST PERSON
When asked in 2008 whether he would be upset if he suddenly lost the title as the world's richest person, Gates replied, "I wish I wasn't, there's nothing good that comes out of that."
2. HE USED TO LEAP OVER CHAIRS AND GARBAGE CANS
In a 1994 video interview with Connie Chung, Gates proved to the world that has hops when he jumped over an office chair in a single bound. Sadly, in a Reddit Q&A session 20 years later, he said that he no longer has the ability to jump over large objects. "Be careful—it can hurt if you don't succeed," Gates warned.
3. HE DOESN'T LIKE TO CARRY AROUND A WALLET
Quick, how many one hundred dollar bills does Gates carry around in his wallet? It's a trick question because, chances are, Gates isn't carrying one. "I don't carry a wallet around that often," he told CNBC.
4. HE ISN'T AFRAID TO GO OUT IN PUBLIC
While Gates does enjoy going to the movies because "they turn the lights out," he said he isn't bothered much when out in public. "Somebody might ask for a signature, rarely, but that's not a difficult thing," he said.
5. HIS BEST PERSONAL FINANCE ADVICE
If you want to become wealthy, should you work on creating the next Microsoft? Gates' advice to someone who makes under $100,000 a year is to "invest in your education."
6. IT'S HARD TO FIND SOMEONE MORE CHARITABLE THAN HIM
Together with his wife, Gates has given away $30 billion since 2000, according to Forbes. To those wondering, a $30 billion fortune would make you the 16th richest person in America.
7. HE HAS A GUILTY PLEASURE
Like billionaire Warren Buffett, Gates says his guilty pleasure is owning a plane. "I do get to a lot of places for Foundation work I wouldn't be able to go to without it," he said." (Hey, after you invest in your education and become a billionaire, you can also buy as many planes as you want.)
8. HIS FAVORITE BURGER CAN'T BE BOUGHT AT MCDONALD'S
9. HE ONCE GAVE A REDDIT USER THE SURPRISE OF HER LIFE
Last year, Gates was assigned to be a Reddit user's Secret Santa in the site's annual gift exchange. A girl by the name of Rachel later apologized when she found out she had asked Microsoft's co-founder for an Apple iPad.