Girth.
I have the impression that people see me as a thin person. Until about three years ago I shared this image of myself. It was always something I took for granted. Then I discovered my midsection. It is the region between your rib cage and your hip bones. Ideally, I would not have a midsection, not that you would notice anyway. For many years I didn’t. Then one day I woke up to the fact that there was some convexity where there used to be concavity. Most people would say that I’m still not overweight (at least I hope so), but I’ve noticed and I don’t like it. I’m not losing any sleep over it though.