When you have a toothache, you call your dentist and ask for an emergency appointment to relieve your pain. You know deeply at that point that not having a toothache is happiness. Yet later, when you don’t have a toothache, you forget and do not treasure your non-toothache.
Thich Naht Hahn from “Savor: Mindful Eating, Mindful Life”, co-written with Lilian Cheung
I can’t really add anything to this other than to say when I worked at a school you could always get the children to laugh when their dental appointment was at 2:30!