Hmmm the weird drained feeling might have more to do with you than others! This thread is utterly depressing. I actually burst out laughing when some posters said they drop people as soon as they stop being good for x, y and z because there were so many selfish people in the world.
Is it not now generally recognised that our society has lost something over the last 100 years, something to do with the rise of the individual identity and the fall of community cohesion? We criticise societies for being fragmented, isolating places, but perhaps this is at least partially our own fault. It hasn't always been standard practice to maintain a small group of desirable contacts while dropping others who were less entertaining or tiresome in some other way. Such behaviour would be considered morally wrong in many cultures, yet some posters here seem to see something laudable about culling their friendship list of people who are not 'true friends' or who have simply become rather dull.
By the way, I don't understand how you can all be amazing friends who would never fail to help someone in need while also editing, dropping, leaving, fading and generally walking away. It makes no sense. How is the friend supposed to magically latch onto the knowledge that last week you provided a willing shoulder to cry on but have since decided that any more of that carry-on would be gratuitous and selfish? They may not have the self-awareness or maturity than you have to know this.
The world is full, of hurting, broken people who need friends and who are unlikely to be able to make any in a world were fun, thriving people will only tolerate individuals as high-functioning as themselves. I don't think community is quite so optional. Perish the thought that some of these self-confessed 'fussy' posters may find themselves sitting in a bedsit one day, achingly lonely, poor, will and robbed of self-esteem, hoping against hope that someone will offer them the hand of friendship.
There are so many threads on mumsnet expressing the pain of rejection in friendship. Perhaps this is why.