Mr M: I like trucks.
Me: You do?
Mr M: Yeah. When I'm a grown up, I'm going to buy a truck.
Me: You'll need a job so you can afford to buy one.
Mr M: I'm going to save all my money, and I'll probably have to walk up and down the sidewalk to find more money* and save it too.
*At least he has a strategy for when he can't get a job because he won't learn how to read.