Hey if I had to catch a bus/train at peak hour right now I'd be wearing a mask too.

You don't really know what that lady's personal situation is. Maybe she's a transplant organ recipient. Maybe she had chemotherapy yesterday. Maybe she's on her way home to care for her mother/husband/child who has a serious auto-immune illness.

TBH I have considered donning a mask when I go out. Not because I think it will protect me, but just to put the willy up everyone else. I reckon it's a really good way of making everyone else nervous enough to stand welllllll away from you and therefore decrease the likelikhood of someone having a good cough/sneeze directly into your air.