I realized that at least for me and my current stage, the obstacle is that I'm afraid to ask. Afraid to ask people to form a bluegrass group with me. Afraid to ask the guy that I'm attracted to on a date. Afraid to invite people to do things that I want to do. All because I'm assuming that no one will want to do these things, and I don't want to look dumb asking.
So my plan is to ask anyway, and keep my mind open to the possibility they might be excited, maybe even as excited as I am. And if they say no, I won't be worse off. I'll just be in the same place I am now - without the bluegrass band, without the date with the specific person I like, without the specific social gathering I want - but a little braver.