With 12 seasons and more than 270 episodes, The Big Bang Theory is the longest-running sitcom of all time. It is also one of the most popular TV shows ever. Right from the start, fans fell in love with Leonard, Sheldon, Howard, Raj, four socially awkward scientists, and their neighbor, aspiring actress Penny. And a few seasons later, as new characters joined the series, such as Amy and Bernadette, fans welcomed them with open arms.

During its 12 seasons, many famous celebrities guest-starred in The Big Bang Theory, including Mark Hamil, the late Carrie Fisher, and Charlie Sheen. Other well-known personalities, like Stephen Hawking and Bill Gates, also appeared on the show as themselves.

In fact, Gates' guest appearance was inspired by one of the writers' first encounter with another celebrity.

The Creators of The Big Bang Theory Took Inspiration From Real Life To Create This Iconic Character

The Big Bang Theory is one of the most popular sitcoms of all time. One of the main reasons for its success has to be its unique characters and, of course, the talented actors that brought them to life. But, did you know that one of the most iconic characters in the show was inspired by a real-life person? As it turns out, the character of Sheldon Cooper was based on someone Bill Prady, co-creator of The Big Bang Theory, met back in the 80s.

In 2009, Prady told the audience at the Paley Festival (via The TV Addict):

"Before I was a writer, I was a computer programmer and was working with guys who were amazingly bright and had a little trouble fitting into the world, me among them. I would tell Chuck [Lorre] about a guy I knew who was a human calculator. If you programmed in Z80 assembly, you had to convert from decimal to hexadecimal, and you could either grab the calculator or you could shout it to this guy, and he would be faster. But he couldn't calculate a tip at a restaurant.

And the reason is because the formula for a tip is 15-20% depending upon the quality of the service, and he couldn't put a numeric value on the service. It was human."

Also, Chuck Lorre revealed that Sheldon Cooper and Leonard Hofstadter are named in honor of actor, writer, and producer Sheldon Leonard.

Something similar happened for the show's spin-off series, Young Sheldon. Jim Parsons accidentally inspired Chuck Lorre to create this new show after showing him a video of his 10-year-old nephew, who is kind of a genius.

Donny Osmond Was The Inspiration for Bill Gates' Cameo On The Big Bang Theory

In 2018, Bill Gates appeared as himself in episode 18 of the eleventh season of The Big Bang Theory. Titled 'The Gates Excitation', this episode shows Penny (Kaley Cuoco) hosting Gates at work because his company was looking to partner with her pharmaceutical company. When they hear about this, Leonard (Johnny Galecki), Raj (Kunal Nayyar), and Howard (Simon Helberg) start planning ways to meet him behind Penny's back.

One of the funniest scenes in this episode is when Leonard finally gets to meet Gates. And, as it turns out, this hilarious skit with Bill Gates was inspired by real-life events. The inspiration was singer and variety show host Donny Osmond, who Tara Hernandez, a writer on the show, met in a very awkward but hilarious way.

"I was in an airport and I see Donnie Osmond. I get this moment of confidence, where I'm like, 'I'm just gonna talk to him.' I'm gonna play it cool [like] I'm a big fan. So I walk over there and I get out, 'Mr. Osmond?' [Starts sobbing] Just like grown woman tears. Just sobbed all over him. And he just was the nicest. He was so sweet about it," Hernandez revealed at Comic-Con 2018.

When she shared this story with the rest of the writers, they knew they had to write it into the show and Bill Gates' guest appearance was the perfect opportunity.

What Did Bill Gates Think of His Time On The Big Bang Theory?

During its twelve-season run, tons of celebrities guest starred in The Big Bang Theory. And, so far, almost all of them have revealed that their time on the show was a blast. And Bill Gates was no exception. The Microsoft co-founder revealed that he was thrilled for the opportunity to appear in this popular sitcom.

"It's fun to have a show where people are allowed to be a little nerdy and a little bit smart, so I can relate to it, so I was thrilled when I got the chance."

He also admitted that the cast was great to work with. "[They] made it super easy. They're total professionals, so it was a blast." The actors had a blast while filming this episode, with Cuoco teasing Galecki that Gates had "landed his jokes better than you have in 11 years."