My son just turned 3 a week ago. He has been talking since he was 19 months old, and now he's talking in full sentences, and not just repeating, but coming up with his own sentences. Example: "We were in the car eating tacos on the way home - he had one of the wrapers on his lap so he doesn't make a mess. He said Mommy, close the windows - I said no hunny, it's nice out today - his reply: but my paper wont stay on my lap and I will make a mess." He is just 3 weeks short of the cut-off to start pre-school this year. He can count to 15, knows all the colors of the rainbow, etc. What can I do to challenge him so he doesn't get bored with school?