Big Bang Theory plot hole: Key Sheldon quote creates error in Leonard's childhood

However, it’s another feature from Leonard’s childhood that Sheldon brings up which appears to have irked one TBBT fan.

Spotting a plot hole, user cornerboyfrank8 points out on Reddit: “In Season 1 Episode 16, they are talking about how Leonard was denied celebrating his birthday by his mother.

“Sheldon says, it was a good method because he grew up to be a physicist, but if his mother also denied him christmas he’d be better at his job.

“In the episode where they celebrate christmas, Leonard says how he never celebrated that, too.”

source: express.co.uk