A more extroverted personality.
I've spent my entire life being shy/introverted/anxious after horrendous bullying throughout High School years 40 years ago! It's led to me not having friends, not socialising, avoiding busy places, etc. I simply can't be "comfortable" around other people.
I spent my 20's and 30's trying to "fit in", making myself go to parties, weddings, and other social events, even training courses, but my stress levels just get too high, I end up stood/sat in a corner and eventually leave early after a wasted few hours.
In my 40's I had the "Eureka" moment of just accepting it's the way I am and I'm not able to change, so I stopped trying to fit in and the last 20 years have been my happiest, just doing what I want to do and avoiding gatherings/parties etc.