Alexander can't decide on a Halloween costume, so he winds up as a pumpkin; he can't decide what to wear to school, so he misses the bus; he can't decide what school lunch to eat, so he winds up with tuna casserole.
Alexander's breakthrough comes on his birthday, when he asks for a sundae with everything but then realizes that chocolate swirl is all he wants. After that, Alexander finds his own decision-making style: not as deliberate as his mother or as quick to decide as his father, but somewhere in between. And when he tells his mom he wants a baby brother, he learns that sometimes "you get what you get, and that can be OK too."