I loved Latin French and German, loathed Physics, feared chemistry and maths, but my absolute deepest loathing was for PE (ie sport). The teacher hated me and I hated her back. The thing is, I was quite fit, a cyclist, and went to judo classes two nights a week, but her nasty attitude was off-putting. The difference between school sport and non-school sport was astounding. In judo and cycling I was encouraged: in school sport I was belittled.
This was at a standard co-ed Grammar School - the kind you went to when you passed your 11+.
I was allowed to drop physics and chemistry, and I got put down to the middle stream for maths, which enabled me to pass the subject - just - at GCE 'O' level.
When Mum and Dad told me I was not allowed to stay for my A levels, even though I got 8 O levels, I fought back a little bit, but the knowledge that I would no longer have to suffer PE probably took the edge off my fight. I gave in and left, and went to work in the civil service, where I was deeply unhappy. My own fault - I should have fought harder.
A bad teacher can have a bad effect on a person's life.