I get it, that's a really bad example. You definitely shouldn't have to resort to lowering your expectations of people, because there certainly should have been a basic amount of courtesy you could have relied on from your 'mate'.I appreciate it doesnt need to be quid pro quo, nor would I expect it to be, but there is noticeable lack of any sort of effort. I spent hours helping a 'mate' the other day with his PC problems, trying to sold an unsolvable issue and then I couldnt get the time of day off him.
I'm just at the point of giving up. I dont know how much more I can take of it, because the isolation you get, that punch of it is absolutely horrible.
You said yourself you have a core group of people in your life you can depend on. You know you have a group of internet strangers in here day and night that you can talk to if the going gets rough. There's a big void in between those two categories but it is one that can be filled. Maybe sign up to some kind of activity, sporting or otherwise, where the aim isn't solely to meet people, but it could be a welcome biproduct?