Think about the last time you had what you call a 'normal social interaction' with someone.

It probably doesn't quite represent the level of manners, thought, or routine that it would have, 10, 15, 20 years ago for a person in your position.

By exchanging voice-to-voice and face-to-face contact for mostly letters (and mostly typed very badly), we have lost quite a lot of the technique we once possessed as a race when it comes to social niceties. People trust less and risk less in interactions. Lasting friendships are harder to come by than they used to be. Ostracism is easy when all you have to do is push a button, and we can now all live in our little high school clique forever, thanks to the convenience of internet communications.

At least, this is how I rationalize it, when people are rude to me. It can't always be because I'm an asshole, that doesn't satisfy my scientific curiosity enough.