I was reading this post Muff, at Kaleidoscope Muff, wrote about some real life friends she accepted at Facebook. She described very well some people's behavior that makes it almost impossible to have any kind of relation.
The pathological liar affects me in a very deep way since my sister is at the list. It is impossible to talk to her because she doesn't only lie about important aspects of life but also about the most silly things. So in every ten phrases you get almost nothing, no connection whatsoever.
There are those who constantly talk about their problems that are always more important and serious than others and insoluble.
Whatever you say is refused usually with the famous sentence that makes the life of therapists hell: "Yes, but...".
You can talk for one hour with a "Yes, but..." person and it will lead nowhere since even small talking is not a possible escape. Than it comes a day that, at least I did, you have to look at the person and say: "No. No "but" this time or anymore."
Usually the person who is in this kind of vicious circle is also a constant sympathy seeker. They complain, whine, whimper in a monochromatic way and it makes you loose all your energy. At the bottom of whatever they say is the sign: "Isn't it awful?"
I'm a person who is very empathetic with other people's suffering but I confess that I learned to avoid wasting my energy when facing this behavior.
No need to remorse because it will not make any difference in their lives for they also don't want your friendship and know that everybody leaves so there are always at least three persons around them.
If one person don't show up it will not be noticed.
You can take a look at "Games People Play", to see more psychological traps that you can avoid. It was Eric Berne, founder of the Transactional Analysis, back in the sixties who did these patterns. I don't like it as a therapy process but it is a good source to understand some relationships you have the suspicion that are a little bit strange. Now I will change the TV channel because I'm in the "Speech, I have the power game." when a head of state talks whatever is in his head, or at the speech script, and we have to listen.
Why do they have to speak like this, in a solemn and rhetorical way? It is so old-fashion!