Earlier quoted context omitted.
You still can. Most people have more and less social periods of their lives. I have plenty of _very_ social friends in their 40s/50s who weren't as social in their 20s. Or the opposite. Life is long, and many of us need decades focused inwards with others focused outwards
How, though, If you never developed social skills?
… Do it; suck. Do it more; suck less.
“How to Make Friends and Influence People” is a great & classic book about giving people social room, focus, support, and attention with genuineness and humour (“influence” isn’t meant in a manipulative sense). Effort and attention are required, and practice, but that’s the cost of change and improvement.