I think once you have children at school and you get involved it does help. I worked in a bank and would prefer to work at the desk instead of being a teller. Being forced to talk to customers face to face did help and I am alot more outgoing now in my 50's than I was in my 20-30's.

To this day I can find it hard to strike up a conversation with someone I don't know. It is easier in a shopping centre as to my thinking you will not see them again. weird I know but that's me.

All that being said I still like my "quiet space" and enjoy days spent at home on my own.