Why?

There is this lady at the gym who works out a'natural....as in she does things like using the stationary rower or the treadmill without wearing a bra. She's probably around 50ish, so lets be honest those babies are not exactly perky. In fact as she was power walking in front of me today the song "do your ears hang low" kept running through my head. Why on earth would someone do that?! I am baffled.