Where's Spot?

Naomi asked me to read "Where's Spot?" to her. It's one of those where Spot (a dog for the uninitiated) hides behind flaps. It reads "Is Spot behind...." and you open the flap and it says "No" and has a picture of another animal. So the first couple of times Naomi did the "right" thing and each time she opened the flap said, "no, it's a ....". By the fourth time she thought it was funny to say "Yes" every time we opened a flap. I think her uncles would be proud of her anarchist tendencies! But sometimes, I wonder if those dudes who say that if your child chooses to re-read the same book over and over you should humour them; if they actually have ever been in that position or if they are just theorists who have never had the tedious experience of reading the same thing repeatedly?