As a teacher, there are several things you have to be prepared for. A kid could vomit at any moment. They have running noses that drip down their faces. And yes, some pick their noses. But, at the age of 3 or so, I can handle that. When I am on a metro with adults, I do not intend to, nor appreciate, seeing someone pick their nose. It amazes me at the number of adults who partake in this disgusting habit. The other night, I had to ride several stops with a man who was relentless. I even made a few comments, even attempting a slam in French. He pretended he didn't hear me, and dug away. I wanted to puke.
Then, two days later, same thing - different man. Come to think of it, I never see ladies picking their noses. Maybe we are just mannered and discreet enough to know not to do it in public. I don't care if you are a nose picker at home, in the bathroom at work, or anywhere else you feel fit, but it is NOT the thing to do in public. I wish there was a law against it. Besides men who spit big hawkers on the sidewalk, the nose picking has got to be the most horribly disgusting thing to do in public. And to think, these people are touching the metro doors, handles, etc. And for that reason alone, I do not go into a metro w/out gloves on. And if I do happen to forget at first, the hand sanitizer gets whipped out and then the gloves go on. :)