Because obviously it's not true. Even if they end up at the same reading level at the end of the year the kid who read 2000 books before he started school will always have read 2000 more books. And likely will have gotten through a heck of alot more in that year the the child whos just learning. The only reason I could think for them to say this is to make them feel more comfortable about the fact their child is average. Or am I missing something?