The challenge of children

I read this post today from a blog called 22 Words entitled "You've already donated, so now donate some more: The loving logic of a 5-year-old":

Me: We already sent some money.
Orison: I wanna send more.
Me: How much?
Orison: 52
Me: OK.
And so we did.

Reading this makes me excited and nervous about having kids. I hope we are challenged by them, and that we respond well to the challenges.