I have lived without a car for several years, so I walked everywhere. Sometimes people would stop me in the grocery store or other place and say "I see you walking all the time. God, you've really lost weight!! What are you doing?" I also worked for an extremely large company. There were probably about 2000 people in the building where I worked. So people I did not know at all would stop me in the hallways at work and ask how on earth I was dropping so much weight, so fast.

I am tall with naturally curly hair and apparently striking features. It isn't terribly uncommon for people to notice me whom I never noticed. That sort of experience goes back at least to high school, where people recognize me and I have no clue who they are. (Edit: This is probably compounded by my crappy eyesight. I sometimes don't recognize people whom I do know until I am practically on top of them.)