I vaguely remember reading Santa Mouse to DS5 when he was 2. At the end there is something like "and i believe, don't you?" DS gave me a look like, "you mean there's some reason not to believe in him?" I just ignored the look and moved on to something else quickly. Since then, he has had questions every year, and we have had to work very hard to convince him that Santa is real (because we think this is fun). This past year, Daddy agreed to take shifts with DS then 4, standing guard by the tree, so he could see Santa. Of course, they both fell asleep. He tried to get me to take a shift, but I of course know that Santa does not come if you are not asleep, and so I went straight to bed! I think he doesn't really believe, but he likes to think there's a possibility of such cool magic. About a week ago, we were dropping something off at my mom's house while she was napping. I said to be quiet not to wake her, and DS5 said, "Grandma will think Santa or the Easter Bunny was here!"

As for Ruf's levels, she herself calls them estimates. Her book helped me to know there even are different levels of giftedness, and that kids' needs will vary widely. (Also, we do have one of those kids who fell into the levels pretty nicely, so the book really spoke to us.)