I tried to be somewhat scientific about my answer....because my son just turned 5, but has always asked a lot of questions!
He is awake for an average of 14 hours a day. I thought about how many questions (on average) I get in a 5-min. time period; I think about 5 (this could be on the low end, just depending, but I think it is a good average). So, that would be an average of 60 questions an hour, for 14 hours that means 840 questions a day. So the 437 questions is totally do-able, but I think it is more!