Maybe because I began as a writer, I have a good ear for dialogue, and maybe being an English major - and that I also read a lot as a kid - if I hear somebody say something that I think's funny, or I find a situation or story, I'll try to work that into the movie.
Because it's me playing the character, trying to find a way to make it believable and entertaining and interesting.
It's not enough just to be real; you have to try to make it interesting or entertaining.
I try to find a way to make it comfortable or interesting or funny to me.