Do you have memories of exceptional teachers who had an impact on you?
I mean mainly positive, but it can be negative as well. Was it something big they did for you, or was their influence made by little and "unimportant" gestures or comments?

I've got both positive and negative. In primary school, my teacher saw I was being bullied but didn't do anything about it. She witnessed how my classmate kicked me in her class (PE). It used to happen 3x a week for 4 years. It's it possible she really didn't notice? This taught me I was invisible and didn't matter.
On the contrary, in years 5-9 I had an old teacher who constantly praised me and used to say how smart I was. He used to drink in the pub with my father. When father returned home, he would praise me because my teacher told him what a great student I was. That I was the best student he's had in 40 years of teaching. That's what gave me self confidence and was one of the few positive experiences in my life under 15. His praise made me study and try extra hard because I was afraid of disappointing him.