I agree that "are you putting on weight" is not the cleverest thing to say, but there are times when I see a woman and I can't tell if she is actually pregnant or just has a tummy bulge. I know that I am not the only one who has experienced this. I know other people who have embarrassed themselves by asking "so when are you due?" questions, and it turns out that the woman wasn't pregnant. There have also been times when I've been on the train and seen a woman with a slight bulge and wanted to offer my seat, but wasn't sure if she would get angry because I was acting like I thought she was pregnant when she wasn't.
Expat, I agree that the blind man shouldn't have been left standing, but why did you single out the young girl out of everyone on the bus? Is it because she was young? How do you know she didn't have a physical disability herself? Not all disabilities are visible. She could have had chronic fatigue, fibromyalgia, AIDS, lupus etc.