The Big Bang Theory

Sheldon Cooper's quirky habit of knocking three times on doors in The Big Bang Theory stems from both practical production needs and an in-universe backstory. Executive producer Lee Aronsohn revealed the behind-the-scenes reason, while the show itself tied it to a childhood misunderstanding. Young Sheldon later added context without altering the original narrative.

December 30, 2025 Reported by AI

A controversial opening scene from the pilot episode of The Big Bang Theory has been excised from TV reruns. The sequence, involving characters Sheldon and Leonard at a sperm bank, no longer airs due to its awkward fit with the show's later tone. It remains available on streaming platforms like HBO Max.