Running for 12 seasons across as many years, there’s no denying that The Big Bang Theory is a fan-favorite TV show that still has a dedicated following in 2023.

However, even the most adoring fans might not know all of the behind-the-scenes secrets from the beloved sitcom.

Revolving around Jim Parsons, Kaley Cuoco, Johnny Galecki, Simon Helberg and Kunal Nayyar, so much happened onscreen, but it turns out that just as much was going on when fans weren’t watching.

We did some digging and rustled up 12 secrets from the show, including details about guest stars who turned down roles (that list includes a massive pop star), actors who were almost overlooked, onset romances, future plans for reboots and more.

Take a look and let us know what, if anything surprised you!

Scroll through the slideshow to check out 12 big secrets from the set of The Big Bang Theory…