The Big Bang Theory: 21 Easter Eggs You Probably Missed

2. Carol Ann Suzi Photo Tribute

The Big Bang Theory was dealt a crippling blow following the sad death of Carol Ann Suzi, the infamous voice of Howard's mother. She's never seen on screen, but she was still had a huge influence on the storylines.

In a recent set visit, a reporter being given the tour spotted a photo of the actress on Leonard and Sheldon's fridge, where it will remain as a permanent tribute to such a hidden gem on the show, part of the reason why it is so successful today.