Comedian Demetri Martin's book is a weird collection of one-line jokes, cartoons, and strange (almost surreal) short stories. It's funny, in a kind of existential way. There really aren't any punchlines and the humor is, at times, so subtle that it can pass you right by. However, it is clever, witty, and most of all, highly entertaining.
When you laugh at Martin's jokes, you instantly feel superior to everyone else who didn't laugh at them because those people, obviously, just aren't as smart or precocious as you and therefore don't understand the humor. And you, of course, can't explain why you're laughing because if you did, it would spoil it.
Martin's one-liners are the kinds of things you wish you were clever enough to post as your FaceBook status updates because they would make you seem so cool and thoughtful. As it is, if you read the book, you'll probably just use his ideas on your FB page because it's not like he's your friend or anything and so won't be checking up on you.
So just read it. It's funny.