Watch: Bill Gates reveals the two 'crazy things' he purchased after he became a billionaire

Microsoft co-founder Bill Gates, who is one of the richest men in the world with a net worth of $91.9 billion, revealed the two craziest things he has ever purchased after becoming a billionaire. 

Gates, who made his first appearance on The Ellen DeGeneres Show, revealed that he bought a Porsche and a plane for traveling.

"I don't have that many things that are extravagant taste, so it didn't change too much," Gates told the host Ellen DeGeneres with a smile. However, he added that he did buy a Porsche.

"So you didn't say 'Oh I'm going to buy a Porsche?'" Ellen asked.

"I did - that I did," he smiled and said, adding: "That was an indulgence, and then eventually for my travel I got a plane, which is a huge indulgence, so those are my two."

"So you have a Porsche and a plane and that's it?" she asked.

"In terms of crazy things, yes," he said.

The self-made billionaire also revealed his concerns about money. "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."

Apart from talking about the craziest things he purchased, he also played a game with Ellen where he guessed the prices of grocery items and it came as no surprise when he failed to answer.

"We're going to test your knowledge of some everyday items that you get at the supermarket," Ellen said, asking Gates, "When was the last time that you've been at a supermarket?"

"A long time ago," he replied to Ellen.

He guessed the wrong price of a box of Rice-a-Roni, a large container of Tide Pods and a bag of Totino's Pizza Rolls.

Check out the video below: