Oh I didn't stay quiet, I developped a good sense of humour and made good friends who appreciated my company and I appreciated theirs too.

I just never got the hang of the shit-talking.

Sometimes the jokes were almost shit-talking with close friends, but never going half as far as my friends took it.

This could only happen after the ''shut up if you have nothing nice to say'' phase which got me friends.

( And never with coworkers. )

P.S. : Oh now I remember : Social anxiety : pathological fear of negative judgement from others.

It's a personality trait you're stuck to manage forever so it stays under control.

Unless you want to end-up freezing with you hand on the door knob because if you go outside, people will see you, and you don't want them to think you exist.

And like you said, managing that involves going out of your way to do things that don't come-up naturally to you : go out and be around people, listen and talk to them.