The “How am I funny?” scene is based on something that actually happened to Joe Pesci. While working in a restaurant, a young Pesci apparently told a mobster that he was funny, a compliment that was met with a less-than-enthusiastic response. Pesci relayed the anecdote to Martin Scorsese, who decided to include it in the film. Scorsese didn’t include the scene in the shooting script, so that Pesci and Ray Liotta’s interactions would elicit genuinely surprised reactions from the supporting cast.