I have some where I have just put the same random thing (not just from question to question, but site to site). The post office recently demanded several for me to set up an account for their click-and-ship system (use your computer to pay for shipping packages, and print your own label; saves a few cents and possibly time). I didn't want to give them my mother's maiden name, so I have written down what I told it my favorite food is. (Of course, ideally I would be keeping the passwords and the security questions in different places, but I'm not nearly that organized.)