I don't happen to have a sense of humor personally, so I don't know what's funny about a character... This happens to be a feature of my life generally.

This quote is about a person who says they don’t have a sense of humor and that it is a feature of their life generally. What this means is that they never find things funny and that it is an integral part of their personality. They don’t find things amusing, so they don’t understand why someone might find something humorous about a character.