You may think you are a The Big Bang Theory expert, but there are still some secrets about the show that you may not know! For example, did you know that Sandra Bullock was originally offered a role on the show? However, the role went to another actor after her team politely declined the offer for a simple reason. With a star-studded cast including Jim Parsons, Kaley Cuoco, Johnny Galecki, Simon Helberg, and Kunal Nayyar, there was plenty of drama on and off screen. We have uncovered 12 fascinating facts about the show, from guest stars who turned down roles (including a huge pop star) to actors who almost didn't make the cut, on-set romances, plans for reboots, and more. One actor even confessed to using their dressing room for hookups. Dive into the slideshow to discover 12 juicy secrets from behind the scenes of The Big Bang Theory...