It's one thing, holding open the door for someone at a grocery store, or the library, or just about anyplace else. But the doughnut shop is a different thing altogether. This is a get-in-and-out-as-fast-as-you-can operation. There's no room for courtesy or chivalry here.
A life-long blessing for children is to fill them with warm memories of times together. Happy memories become treasures in the heart to pull out on the tough days of adulthood.