I think the suicides in my first book came from the idea of growing up in Detroit. If you grow up in a city like that you feel everything is perishing, evanescent and going away very quickly.
You're over there in the corner either thinking about the dead dog or whatever, you're bringing up your personal life and you need the space, and then somebody throws you a joke. Especially if it's an emotional scene, you don't want the joke.

