Socially Retarded

I've decided that some people just shouldn't associate with other humans.
I am one of those people.
All my life I have tried to "fit in".
I've never had allot of friends in my life. I usually have 1 or 2. I've not had any friends that have lasted all my life.
In my early 20's I played in rock bands. I was the lead singer. "Friends" came out of the woodwork. I would walk into a bar and people would be all around me buying me drinks. Yet my phone would never ring. My date card empty.
When I left the band, the "friends" left me.
I have a hard time making friends. I have a hard time keeping them.
No one ever or has ever called me to go to movies or shopping. No one has ever thrown me a birthday party, aside from my Mom.
At the age of 43, this still baffles me as I have always been the shoulder to cry on, always available, thrown birthday parties, always given the gifts that "mean" something....etc...etc... Never asking anything in return.
Aside from a Birthday cake made from scratch and sent from another state, I've never received a heartfelt gift. I can count on 1 hand how many times in 43 years I've been asked out on a date.
I have never been accepted into any "clique" at any of my jobs or when I was in high school. Even though I have excelled at all my jobs to the point where everyone knew who I was. In High School, I was known for my singing.
Is it because I refuse to attend any type of party that resembles "Tupperware" or "candle" sales?
I have no clue.
I've attempted at gatherings with new people to have casual conversation (the weather, movies, et. al). I've tried deep conversation. I've tried debate/discussion. I've tried the opposite by being cold, snobbish, etc..
To no avail.
For some reason I always get looked at like I'm from Mars.
I've had people just turn and walk away from me.
So I have just come to the conclusion that I am socially retarded.
Had the Internet been as popular back when I was 25, I'm sure I would have lived my life online.