How was your upbringing? Did you have to use things like public transport when you were young?
I imagine some of the early exposures and immune system build up might have good impact later on in life.
I am not germaphobe. When people saw someone with flu, they would stay away, i was indifferent. I'd just tell them i am ok with the risk, and most likely i would not even get sick, or if i did, it'd be a very very mild one. I never did.
The moment i read about covid 19 and lack of evidence for touch based spread (which was very very early on in pandemic, really), i stopped caring about many things (but ended up still doing some for a while because my wife asked me to). We still met with some people etc.