Fact Snacks!

in-goodfellas-the-am-i-a-clown-do-i-amuse-you

In Goodfellas, the ‘Am I a clown? Do I amuse you?’ scene, where Tommy DeVito (Joe Pesci) attacks Henry Hill (Ray Liotta) for calling him a ‘funny guy’, was Pesci’s idea.

He’d once worked at a restaurant where he got a nasty reply after telling a real-life mobster he was funny, so he suggested it to director Martin Scorsese, and they filmed it without a script to get genuine reactions from the cast.

(Source, Source 2)