We got him a cheap one to teach him the time concept at 7. Now at 9, he wears it all the time. He goes to a park at the next block and I tell him to be home at 6:30 and he will. I tell him to be ready for x, y and z in 20 minutes and he is (or doing his best to be). We're in the car rushing somewhere and he tells me, don't worry, we'll make it, we still have 13 minutes. He doesn't carry a phone so his watch helps him be responsible and independent.