CBS’s The Big Bang Theory is one of the most popular shows on television today. But  like any popular show, there’s a lot that goes on that the fans might not realize.

Here are some of the most incredible little-known facts about the show. How many of these did you know?

1. The cast and crew of the show are fairly superstitious. In fact, the show’s creator, Chuck Lorre, once joked that it would be bad luck for him to ever sit in a chair with his name on it. The crew ran with it and so he’s never had to do so.

2. Jim Parsons isn’t a Star Trek fan. Despite his character’s love of all-things-nerd, Parsons has admitted in interviews that he has never watched the Star Trek tv series.

3. Mayim Bialik is real world smart, too. The actress who plays Amy Farrah Fowler is not just playing smart. Bialik has a doctorate degree in neuroscience.

4. Johnny Galecki and Kaley Cuoco, who pay Leonard and Penny, dated for about two years toward the beginning of the show’s run. They later split up despite their characters dating on the show.

5. The famous apartment from the show might be one of the most well known sitcom sets of all time. Most people don’t know it is supposed to be located in Pasadena, California at 2311 Los Robles.

6. It’s popular abroad… maybe too much. A show called The Theorists started in 2010 in Belarus that wasn’t just similar… it was a total ripoff. In fact, once the cast was informed they quit the production.

7. Most of the characters work at the California Institute of Technology (CalTech). But what’s even better is that the audience that watches the show get filmed is often full of CalTech students!

8. Leonard and Sheldon are named after legendary TV producer Sheldon Leonard.

9. The coffee table in apartment 4A is often full of little easter eggs like Mental Floss magazines and Red Vines — all things the occupants would clearly enjoy.

10. The character of Penny was originally named Katie and played by actress Amanda Walsh. But after filming the pilot, the showrunners decided she came off too harshly and they reevaluated the character. The result was Penny!

11.During the filming of season four, Kaley Cuoco broke her leg while horseback riding. She missed a few episodes and then filmed behind a counter. Mayim Bialik, meanwhile, was in a car accident and broke her arm but continued to film.

12. Usually, when a show is renewed it receives a one season renewal. In 2011, TBBT was order for three more seasons at once. CBS did the same thing again in 2014. That’s a lot of confidence!

13. A Brazilian scientist discovered a species of orchid bee in 2013 and named it “Euglossa bazinga” after Sheldon’s famous catchphrase.

14. The theremin, which is not easy to master, is actually being played by Jim Parsons on the show.

15. When Parsons got the call to audition for the show, he didn’t know who Chuck Lorre was. He actually thought he was auditioning for a new show from TV game show host Chuck Woolery.

16. Jim Parsons and Kaley Cuoco are the highest paid actors on TV.

17. This is the apartment layout.

18. The smile? That’s all Jim Parson’s doing. The writers simply put a direction for a strange smile and trusted Parsons to make some magic. And that’s exactly what happened!

19. The spanking itself was supposed to take place off-camera but everyone liked it so much that they kept it in. Also, he is really spanking her!

20. We still don’t know Penny’s last name.

Who knew there was so much going on behind the scenes on the show? I also don’t know if I can forgive Jim Parsons for not being a Trekkie in real life. Come on Sheldon!