The 62-year-old Microsoft founder sits down with the daytime talk show host on Wednesday's episode, and opens up about what it was like to become a self-made billionaire in his early 20s.
When asked if he was ever concerned with money, Gates admits, "Mostly I loved software. I do remember at the private school I went to there were other kids whose families were better off -- like they had a Porsche or something, but it wasn't that big of a deal."
Gates notes that he was "stunned" when Microsoft "ended up being so valuable." The company went public when he was 30, and it was then that Gates started making some big purchases.
"I don't have many things that are extravagant tastes, so I didn't change too much," he confesses with a smile.
Gates did, however, buy a Porsche. "That was an indulgence," he quips. "Then, eventually for my travel, I got a plane, which is a huge indulgence."
When DeGeneres asked if his only indulgences are the Porsche and the plane, Gates adds, "In terms of crazy things ...we have a trampoline room in our house. The kids love it. Indoor trampoline, I recommend it."
In addition to his interview, Gates also plays a game with DeGeneres where he guesses the prices of grocery store items.
Gates gets off to a rocky start when he wagers that a box of Rice-a-Roni costs $5 when it usually sells for $1. "I'll take five," he exclaims.
It's been a big week for Gates.
On Tuesday, ET learned that the businessman will be guest starring as himself on an upcoming March episode of The Big Bang Theory. Gates will be stopping by Penny's work and when this news reaches Sheldon, Leonard and the rest of the geektastic gang, the guys do everything in their power for a chance to meet him.