I was just having a random thought earlier that a lot of people seem to consider time to be the measure of friendship, when being acquaintances evolves into friendship and how strong that friendship is.. But it doesn't seem to be that way - in my life at least. So, I was thinking, what possible circumstances have to occur before you declare someone a friend. Perhaps going through a traumatic experience together? Maybe just due to similar opinions ? How do you decide when someone is a friend?