Do you think it's weird..

Um, yes. LOL!

Well, I would think someone who's doing it is weird. But I guess then I'd figure, well, they must be particularly vulnerable or colds/flus are particularly dangerous to them. I'd say for a 100% healthy adult human being, it's weird.

Ok, well that puts you in the 'colds/flus are particularly dangerous' category, so while I think you should expect stares and weird looks, you're justified. So you either care or you don't. Why don't you just carry a bottle of hand sanitizer with you so you can wash your hands the second you step off the subway?

I bet it (wearing the mask) helps, but not for the reason people would think. As I understand it (and I'm no disease vector expert), it's not airborne germs that get you so much as touching germy things and then touching your mouth or nose. So the mask would prevent you from touching your mouth and nose.

I'm also of the mind that getting little illnesses now and then isn't bad for you in the long run, that it'll boost your immune system (this is, of course, with the caveat that you are a generally healthy adult). I try to keep things pretty clean, but I won't use anti-bacterial soaps because a) a little dose of germs now and then boosts the immune system, b) that stuff build up the bacteria's resistance, c) anti-bacterials stay in the water, you can't treat them, so they end up in streams. I think the anti-bacterial craze is a real bane to public health.

Short answer:  Yes!

Long answer:  Yes, it would be weird if you wore a mask!  However, if you are particularly susceptible to cold/flu's then by all means do so and the heck with what others think!