I think for me it’s my social anxiety, among other things. I just don’t feel comfortable around people like I used to in the past. I however think/hope that if the “right” people come along I’ll feel at ease socializing with them.
I don’t like being around strangers and the idea of meeting someone new makes me nervous - especially if we don’t get along well. I’m picky with people. But yes my paranoia plays into this.