I don't know how relevant it is to respond to the original post after 15 pages of replies.
But I do feel similar feelings to what you are describing, but perhaps for not the exact same reasons.
I have learned who I am and what I like, and I feel those things generally don't fit in with modern society. I do not enjoy much about the US culture (and possibly most cultures). I feel our cultures have been intentionally misled and tainted, and people's interests are based off of this poor influence.
What I basically feel like is that my interests are not attractive to most people's, and many of their interests and activities are not attractive to me. So this situation gives me the feeling of being out of place, not belonging, feeling invisible at times, etc.
I know there are people out there that are like me, but there aren't enough of us to be likely to find each other, and most of us are hidden away, having given up on humanity and society, and we often don't discuss the way we see things and how we feel, because it isolates us even more from people.
I have lost hope to a great extent. I often see people I am attracted to, genuinely good people with beautiful souls, but I always feel that they aren't right for any form of friendship for me. Regardless of how good they are, they typically are just different in ways that I feel a lack of a certain type of connection that I desire.
I am willing to admit that the problem is with me, and that the world isn't going to change, but when I have tried to change and to adapt, it hasn't worked well for me, and has left me in a place I don't want to be.
Perhaps it is just some kind of personality disorder. I don't know. Perhaps a lot of it has to do with our ailing culture, and how it alienates those who don't follow along its ways.
I am not the type of person to give up. I always analyze and assess what can be done, but I have felt this way long enough that I have come to believe that I am not someone people have interest in spending time with, and it seems the majority of people I have no interest in sharing my time with as well.
So I spend my days reading what people say, what they think, watching people and listening to people. Some people I like, even though I feel that I wouldn't connect well with them, and many people dishearten me.
I have found this forum with people who may not be very much like me in some ways, but they feel similar to me in their social experience. Perhaps it is comforting, though I don't know how helpful it is. But I guess it's the best I've got now, so I am happy to read and participate with people in similar situations as me.
To all of you who feel like ghosts drifting through life unnoticed, I do sincerely wish you find genuine lasting connection with others that you desire and need. And for those of us who are too damaged to be able to obtain that, I wish you healing and discovery of the wisdom and truth of life that can lead you to the path that you seek.
Sorry for the long post, but for what it's worth, it seems therapeutic to be able to share and express this feeling that many of us seems to experience.