Outside looking in

I have, for most of my life, felt like I was always on the outside. Never the popular kid or part on the in crowd. Now don't mistake that as a complaint. I have on occasion tried to fit in and usually find it to be way too much effort with little or no benefit. I remember in high school wanting to be part of a particular group that a friend socialized with. After spending months hanging around the periphery and generally feeling ignored, I walked away. I am pretty independent that way. But then I heard it said, from the group of girls, that I was stuck up because I was ignoring them. (Isn't it amazing how you never forget some things?) I never spent much time, after that, trying to belong to any group. I was happy to have one or two friends...that were happy to have me. I am who I am...and like everyone else, I have been shaped by my life experiences. I am a strongly independent person. I do not generally rely on others. I can do it myself. I am not afraid to be alone. I don't think I know how to be part of a co-dependent relationship. I'm not sure I want to learn. I am perfectly happy just going on, on my own. But what happens when there seems to be some expectation that you will operate as part of a single minded organism? Or maybe that's just me looking in at them. They've had months, and just each other, to grow and create something from nothing. I step in, invited and welcomed, but it seems, mostly still standing around the periphery. I don't want to distance myself but I'm not sure I know what to do. I will always be behind. I can never catch up with the time they've already spent together. I don't know how to go from a lifetime of solo independence and self-reliance to being part of a...team?