From Penny’s new flames through to Stuart, the comic book store owner, we’ve grown to love pretty much every character that’s walked onto the set of The Big Bang Theory. However, have you ever wondered what the people behind the characters are actually like in real life?

John Galecki as Leonard Hofstadter – Then

Leonard is an original cast member, appearing on the show since the airing of the pilot. His character is the best friend and roommate of fellow star, Sheldon Cooper. The pair work at a university where Leonard is an experimental physicist who often comically gets annoyed at his best friend, but ultimately  always ends up forgiving his behaviors.

His neighbor across the hall,  the beautiful and cool Penny, captures Leonard’s heart from the beginning of the show, with the two finally marrying during the ninth season after years of on-off dating.