another reading journal

I am reading "The name of this book is secret" the quote : "question : what is not enough for one, just right for two, and too much for three? answer: a secret." I don't know why I picked this quote, I guess I just like the randomness to it. It is a joke in the book that I get but I don't really see how it's funny. I am wondering if anyone else who hasn't read the book gets it.