While Jim Parsons' exit came as a shock, Kaley Cuoco revealed in an interview an unwritten code that everyone on set followed.

The Big Bang Theory changed the entire sitcom landscape when it premiered in 2007. Whether it was Sheldon's knocking or the science jargon, the four odd scientists or Penny, the show had plenty to ensure it tickled the audience's funny bones.

The beloved show ran for 12 laugh-filled seasons and ended in 2019 with Sheldon and Amy finally winning their Nobel Prizes. Although this is what the audience saw on screen, the story behind the end of the show had a specific unwritten rule, which Kaley Cuoco revealed in an interview.

The science-inspired comedy show ended a while ago. But the actors still remember the wonderful times and days they spent together while filming it. In a 2021 interview with Variety, Kaley Cuoco reflected on her memories of the sitcom and described the day she learned it was ending after its 12th season.