I know a bit about it because I’ve suffered from anxiety since I was about 10. However as you say back then (early 80s) it was just how I was, and I didn’t get a formal diagnosis until I was in my mid 40s when I had a bit of a breakdown
I’ve learned a lot about how my brain (mal)functions over the last decade and for me personally one of the manifestations of my anxiety is that I’m incredibly organised - everything is planned and replanned, checked and double checked, notes written, copies made, to the point that my consultant said I could get a formal OCD diagnosis if I wanted another label. He’s funny like that
Because of that, when I read of cases in D&P where people are anxious but didn’t have a ticket, used an expired railcard, bought on the train etc I find it almost incomprehensible, but I have to remind myself no two people are identical.