My one-year-old sits in his highchair, cramming watermelon into his mouth. He can’t get it in fast enough. In between bites, he fusses. If there’s not a spare piece or two waiting on his tray, he complains. Despite the fact that we generally give him as much watermelon as he wants, he still fears a shortage. As I watch the scene unfold over lunch, it hits me. My son thinks I’m holding out on him. And in a sense, I am. I don’t want him to fill his mouth so full of watermelon that he chokes. So I give him a piece or two at a time—then wait for him…