“What do you do?” There's no doubt work defines a person's identity in a number of ways
It's used to pop people in boxes. Adults have all of these filing categories and pidgeon holes all ready to go.
What do you do is simply a question such that they can pop you into one of their boxes.
A couple of years ago at parties I was in my 30's and retired. I was a boring rent collector....at home, twiddling my thumbs.....doing whatever I wanted whenever I wanted.
Saying I was "retired" as an answer simply infuriated the questioner. They were all ready to pop me into a box, but the answer gave them nothing. If they were older, say in their 40's or 50's or 60's, the answer simply didn't compute on their radar.
I'd have retorts like "Don't be silly, I've got sons older than you, no really, what do you do ?"
It got waaaay too messy in the end, cos they'd be constantly scratching around looking for a box, any box, to pop you in. No-one likes a smart-@$$ answer that is abnormal.
Saying you're an engineer is safe and comfortable and doesn't mess with anyone's head. I found giving that answer put everyone at ease, they popped you in their preconceived box reserved for engineer's and the night moved on seamlessly.
Almost everyone thinks engineer's are such boring dead ****s they never ask any other probing questions. They move away and I keep fumbling with my calculator and pens in my top pocket.....everyone goes away happy.