Thanks to all of you for your thoughts. Graham is a really happy, well adjusted kid, I think. He's affectionate and talkative with us and seems really happy. Something Kriston said struck me. He is a bit shy and introverted and he is used to spending time by himself. Maybe I notice the numbers thing (and it disturbs me most) when it manifests itself in settings where he is encountering other people. Maybe the numbers thing is, in part, a social defense mechanism for when he's feeling uneasy.
He has a t-shirt that he likes to wear that says Go Play Outside. I think I need to take his shirt's advice this summer and get him to the park with friends as often as possible. Then again, his favorite thing to do at the park is to have me push him on the swings while he counts. As in "We'll stop when we get to 286. Okay, mommy?"
I will bring this all up with his pediatrician at his 3 year check up in July. I'll make it a point to ask for a few extra minutes when we make the appointment so she'll have the time.
In the meantime, when we're at home relaxing, I'll make some boundaries and let him go. And yes, I have a feeling that after I go find a toy cash register for him to mess with at Christmas this year, he'll probably be on to something else.
