I've never, ever been as stressed out as during school, grades 7-12. If the rest of life had been that stressful or worse, I'd have checked out a long time ago.
Every single time without fail (except maybe the jump from kindergarten to school) what actually happened was that the adults around me breathed down my neck a little bit less and I got access to a little more freedom to do fun stuff.
Being a kid in school is horrible. You're entirely reliant on your parents to buy you everything and enable you to experience things, nobody trusts you, everything is full of arbitrary rules.
The jump from school to university was especially stark - I kept being told it was going to be really hard, I'd need to work way harder than in highschool etc etc. Turns out what actually happened was I went from 6 straight hours of unavoidable class a day to maybe 2 or 3 much more interesting ones that were recorded and posted online and could be skipped when needed with no consequence, roughly the same amount of homework and I got to live with people my age 5 minutes walk from a 24 hour McDonalds.
And working... they pay you quite a lot of money to be there (seriously even a minimum wage job is unfathomable to a kid, do you know how many gameboys you could buy with that?), there's no homework and you get to do something you're really good at.
Also, all that, plus you're not getting paid for it.
I'm sure experiences differ, but mine was that school was trivially easy and inconsequential, but sometimes time intensive.
I wouldn't consider a job where I have to go and listen to a boring presentation for 8 hours a day stressful. What is stressful is the rat race and making sure I can afford mortgage payments
Before that period? I don't remember much. After that period? Everything gets downhill. Being an adult in a society sucks and I hate it. Normal people lifestyle, with its routines and "work/life balance", with everyone around you having expectations around random customs, with having to do everything in tiny bite-sized chunks, because there's not enough time left after work, chores and family - that's just not compatible with my mind.
Yeah, I guess, this could be a mental health issue.