The other day (Was it yesterday? This week is ten years long), eatmisery cited the old teacher adage, "Don't smile before Christmas". It's used in educrat circles to illustrate to teachers how hard it is to get strict later. If you want a rule enforced, it's best to start off hard and ease up later. I mostly tend follow the idea, but strict looks different on me. I am able to smile. Sometimes I even mean it. So I do smile at kids before Christmas.
Adults? Now, that's different.