Maybe the dude had hearing problems and due to the fact that he can't hear well, didn't figure he needed to speak and you'd get the idea if he just pushed you out of his way. Or maybe he had some dementia issues (Alzheimer type things) and that makes some patients afflicted with that kind of rude and impatient.
I disagree that anyone has earned the right to be abrupt. Ill manners is something that someone may have an excuse for, but never a right to.
Where I live, I see all kinds of people, elderly and young, rude and polite. I try to be kind and courteous to everyone I come into contact with, and usually I've discovered that I can change someone with a foul mood into a more patient person by responding kindly to them...others are just going to be impatient for whatever reason they have. This didn't use to work when I was younger though. I think you have to be "mature" for the nice-routine to work on older people.
of course no one should be rude because of age
it happened to me before in the supermarket little old lady almost ran me down with her cart.
i just prefer to see the humor in my situation it just
seems to follow me around it was meant in fun at myself 
