Foot guy

There is a man who rides the 5 train in the mornings who I simply cannot figure out. He is almost always in the second car from the front, sitting on one of the long blue benches in the spot nearest the center doors. His age, ethnicity, and motivation are beyond me. He appears to maybe be white, but he is pretty tan-ish, and there is something in the way he looks around that implies that he is not American by birth (this may sound silly, but the longer I'm in New York the more I find I can actually pick out the foreign people from a crowd by their mannerisms and bearing). He wears a diamond earring on the right side, and he has shoulder-length, sparse, wispy, but very well kept, straight white hair. Light eyes that move around constantly. He seems to be interested in everything going on around him; it's difficult to get a good look at the guy, actually, because he's so alert that every time a head moves in his direction he notices and turns to look. I've found myself looking him square in the eye many times. But it's difficult not to want to look at him, because here's the thing: he is always barefoot. I don't know why. Nothing about him suggests extreme poverty or homelessness--he is always clean, his feet in exceptionally good shape, not particularly dirty or gross. He wears nice enough jeans, rolled up to just below the knee, and everything jutting out from below the cuff is bare.
He is always in the same place when I get on the train, and I have never seen him get up from his seat. He usually has a black drawstring bag under his seat, and I've tried to sneak a few peeks at it to see if there are shoes in it, if maybe he just likes to be ON the subway barefoot, but puts on shoes before he disembarks? From what I've seen it doesn't seem lumpy enough to contain shoes, but then, every time I try to look at the bag, he notices me and looks up and I feel awkward and look away. Someday I'd like to go over to him and ask him why he never wears shoes, but a crowed train early in the morning just never seems the right time or place...