A depressing truth about people is most of them are entirely ego driven and in their own heads all the time without any real concern for others as people. That doesn't mean they hate you or are consciously manipulating you. Rather that they are so ego driven they don't focus on anyone but themselves. They literally don't think about you unless you are in their sphere. These are the people who don't call back, who never maintain relationships with someone just to maintain them, and make you feel alone. It's not your fault unless you are just being a total twat to everyone and won't admit that. Once you face that most people are literally up their own arses nearly all the time...it explains a lot of behavior. It makes it easier to not take it personally AND to recognise the good ones.