Thank you for writing. It’s certainly possible that you are right that you built a defense mechanism in response to early rejection. There’s an old expression: “You can’t fire me. I quit.” It’s possible that you protected yourself from rejection by deciding that you didn’t care about acceptance. This isn’t to say that you consciously made up your mind to give up on people. Little kids don’t function that way. But they do learn to stay away from what hurts them. What makes me very, very sad in your story is that no adult recognized the problem or protected or helped you. No little kid should be subjected to that kind of cruelty. No little kid should be left to figure it out on their own.
No. It’s not “normal” to be a complete social isolate. People tend to be pack animals. They need others around them to survive and thrive. It’s not necessary to have a huge circle of friends to be okay. Some people are fine with only a couple of close, intimate friends. Introverts are as okay as extroverts. I would just hate to have you go through life without the support, warmth, and mutual trust of real friendships. Yes, you really would be missing something.
You say you have next to no motivation to change. You didn’t say you have none. I suggest you use whatever little motivation you have to explore your feelings about this issue in the safety and acceptance that therapy can offer. A therapist won’t try to talk you into being different. But he or she will help you take a new look at your early experience as well as your present life. Together you’ll decide if you have some goals around relating people that you want to work on.
You didn’t get the help you needed as a child. Your adult self can make sure you get some support and guidance now. I hope you will give yourself that opportunity.
I wish you well.