Answer and Explanation:
By mocking himself Sedaris causes humor in the text. This gives readers access to a light and funny, entertaining and interesting narrative, mainly because Sedaris only makes fun of himself and the funny comments about other characters do not include mockery and sarcasm.
This sends us a message that we shouldn't make fun of people, we don't need this to have fun and besides, we don't know other people deeply, so we don't have the right to make fun of them, but we can do that with ourselves, because we we know deeply and we know our limits in relation to humor. An example of Sedaris' mockery can be found below:
“If a person who constantly reads is labeled a bookworm, then I was quickly becoming what might be called a tapeworm.”