It was partly because my parents forced me into a scholarship that was tied to teaching afterwards - I was entirely unsuited to being a teacher, but neither of them even attended high school, and to them being a teacher was the pinnacle of achievement. I was pretty good academically but university overwhelmed me, so between that and no incentive to succeed, I failed miserably, only passing a few courses. I ended up getting a professional qualification (not a degree) in my 30s and had a decent career.

Living in a squat for a few years showed me I would have made a fantastic electrian or plumber, but you had to have a penis for that for some reason.