I have witnessed impatient parents scolding their tantrum-throwing children in more stores than I can count. The scenario usually goes something like this: Child: “Can I have this?” Parent: “No. Put that back.” Child (louder): “But I want it!” Parent: “I said no.” Child (louder): “BUT I WANT IT!” Parent (louder): “1…2…3…” Parent tip: “I’ll…