Some you can trust and some can't. some you can understand and some can't. some can be jerks and some can't.
What else is there about friends that some go and some stay.?
you can't call them all friends. people come and go in life. friends come and stay for a long time. if you are able to determine which is your friend and who is not then i think the problems will be solved.
The reality is life comes and go,that's why friends comes and go too,friends have good and bad memories to share,they made our life complete and complicated.