When I was in 4th or 5th grade, there was a new student at my school who picked me to be her best friend. She started to get mean when I would talk to other people. She would tell me what to do, then have a tantrum when I resisted. As a natural introvert, I didn't always want to have someone dragging me around and making me do stuff. She was only at the school for about a week before her parents pulled her out. I'm not sure whatever happened to her. I don't think she had any idea what a friend is. At that time in my life, I didn't really have any idea what a friend was either.
I don't have a best friend, and I don't want one. I try to have an equality based social life. I value each and every person who comes in and out of my life.
I have a lot of friends who I love and care about, but I know how it feels to have a friend who is important to me tell me about their "Best Friend." It feels like I'm being rejected, and I could never hope to achieve the type of importance which the "Best Friend" has achieved in their life. It's safest for me to just sort of file that sort of statement.
If you're my friend, you're my friend and that's that. I'm not going to rank you above or below anyone else. Maybe I only see you once a year. Maybe I see you several times a week. Maybe we mostly chat on Facebook because your life is busy. Maybe I see you at the Y all the time. Maybe I haven't seen you in ages. What would factor into the "Best Friend" ranking system? How would I choose? Is it like with a romantic partner where the feeling has to be mutual? It's too much for me to think about. I guess I wouldn't really want to find out if any of my friends like me less than I like them. I'd rather be blissfully unaware of that one. Having never actually been the most important person in another person's life (I am excluding situations in which that distinction was only used to manipulate me into doing things I otherwise would not have done) I guess I feel perfectly satisfied to stay out of the whole ranking table when it comes to friendship.
The bottom line is, I'm too old for high school bullshit, so I at least try to be mature in my dealings with others, and leave the immaturity for the coffee shop.