My experience lasted 2 years (yay school). For the first 2 years of high school I had the WORST math teacher ever. He would constantly call us useless, idiots, that we will do nothing in our lives, failures, and the list went on and on. If a student didn't understand something and asked a question he would first call the student names for not understand then proceed to explain what the student didn't understand ONCE and if the student still didn't get it then the rant begun, yelling at the whole class for no reason. He would do that at EVERY SINGLE CLASS. At a parent-teacher meeting my mom asked him what book she should buy for me to get better at maths since I wanted to get better grades and he told her "she doesn't need any books my lectures are enough" and left. He once asked me to solve a problem on the white board and I was so anxious I started sweating, trembling and getting dizzy. I couldn't concentrate and didn't solve it, I must've spent 5 minutes standing still, seemed like an eternity, with the marker in my hand looking at the board then at him, and he had the most condescending look on his face even when I started tearing up because of my anxiety. Nobody made fun of me for tearing up since they knew what an asshole he was and that they could be next. He didn't give a shit I cried. Another time I actually solved the problem and he was so surprised that I was actually able to understand maths that he made a huge deal out of it in front of the whole class saying things like "I didn't expect you could even do it". Needless to say he made me hate maths, I skipped his classes on purpose, there where even days where I couldn't get up from bed because of how bad I felt and I developed even worse self esteem issues, since no matter how hard anyone tried, if you weren't perfect it wasn't good enough for him. At least for the last year of high school I had an awesome math teacher that I could understand and he was really helpful, and now I am studying what I love in college which is nice :).