I started flossing today, after a prolonged but unintended hiatus (I, um, forgot). Wow does my mouth hurt. I mean, I'm going to keep it up, because it's health and because long term I like how it feels, and because I know if I keep it up it won't hurt anymore. But short term? Ow. It isn't even so much that it hurts, as that it is sensitive. I am so aware of the teeth and gums right now it's a bit distracting.
Also, I would like to point out that the downside of the pleasant Southern California climate is that it is always construction season. Always. Especially in my neighborhood. It is very loud, and like my mouth pain, rather distracting.