I don't know if I've just started noticing it or if people are getting worse, but I find that more and more, people are self absorbed to the point of rudeness.
I don't know how many times I'm in a conversation with someone when someone else who knows them, just bursts in an starts talking over the existing conversation as though their mere presence clearly over-shadows whatever drivel we might be talking about. Now, it's not that they think all that out, but if they weren't so caught up in themselves and had some awareness of other people, I don't think they would do that.
There is also the attention span deficit. Even if you are in a conversation with a person, it's all too common for them to just cut you off mid sentence to talk about something completely unrelated. So you are left, in the middle of your story with your proverbial dick in your hand. What do you do? Do you interrupt them back? Do you point out that you weren't finished? No, if you make too much of a scene, you end up looking like a jerk, even though you are the one who has been screwed in the first place. Again, this type of person is so wrapped up in themselves, they've lost all awareness of common courtesy.
The one that kills me the most are the people who don't even wait for the answer to their own question! They *think* they want to know something which you can answer, but alas, once you start to talk, they realise the sound of their own voice is so much more appealing. So, just shut the fuck up while I stand here guessing what the answer to my question is.
As someone who is a very attentive listener, it pisses me off no end that I can't be granted the same courtesy from so many people. Sometimes I find myself rushing through stories and leaving out vital details because I know the attention clock is ticking. The end result is that my story makes little sense and fails to be interesting. This only happens with people I know will zone out, so either way, they aren't going to get the story. I guess the self absorbed person in question is too distracted to even notice.