you never leave until after the credits!
When my friends and I went to see the Lego movie, we were the last ones out of the theater.
My brother (who was a projectionist until a year ago) really hates people like you, lol.
And he really really hates films like Pirates of the Caribbean and the Marvel Cinematic Universe for making post-credit scenes popular.
The longer the audience is sat in the cinema the longer he has to wait before he can turn off the projector, clean the room and close for the night.
Everytime we go to see a movie with him we wait around for ages now, just because it annoys him.
It's even greater when there's nothing at the end of the credits.