Age-ism

In my new position, I'm meeting new people every day and almost always there is some sort of comment about my age. Whether it is hidden "well, at least you don't have to worry about getting grey hairs from this job" or "I wasn't expecting someone so YOUNG, I was expecting to meet an older lady" there is always some mention. It's somehow acceptable to make comments about age that way. I wonder what would happen if every time I met someone I talked about how old they were or commented on their grey hair or baldness.