My DP doesnt get it either. Used to get v annoyed when I had to work on weekends or evenings instead of going out etc. It didn't compute, no matter how many times I explained that I couldn't just rock up to school the next morning and say to Y11, "sorry guys, no lesson today - I went to the cinema last night instead." I don't think his age helps, in that we both have vague memories of lessons in the 90s in which the whole hour was spent doing textbook work or writing a story. Most non-teachers don't realise how much expectations have changed in terms of the regimented structure of lessons and what they need to contain.
On more than one occasion, he's expressed concerns that I'm a workaholic (I'm really, really not) and can't accept it when I explain that working some evenings and a few hours on a weekend is the norm in the profession.
Recently I've gained a TLR which is very full on and begins in September. However, there are some things which need prepping beforehand so I'm doing some work from home a few days this summer. He's very huffy and keeps reminding me I'm not being paid yet. I know that the school can't reasonably expect me to do the work unpaid during the holidays, but as I keep explaining to him, I'm going to have to do it sometime so I'd rather do it at home, in the garden with a beer, than having to do it all in September alongside the usual chaos of a new school year. September me will thank August me for doing the work. As, I pointed out, will he when he doesn't have to spend the first term coaxing me through stress related burnout.
It's a tough job and there is something systematically wrong that teachers are having to do it. But it is where we are and, tbh, well-meaning friends and family huffing and puffing on our behalf, often constitute just another later of stress to deal with.