What do I write about?

When I tell other comedians that they should write every day, they usually say "What do I write about?" My advice is to write about all the different stuff you enjoy reading about. Let's say you enjoy reading about Jewish gangsters, like one of my best friends does. Then write about it. Who is your favorite Jewish gangster? Do you think Jewish gangsters refuse to carry out hits on Saturdays? Do you think they buy their guns wholesale? Remember, it doesn't have to be funny, but it has to be interesting.