My high school calculus teacher's last sentence to me.

I was a really shitty student in high school. It's not that I got F's or anything, but that I just couldn't bring myself to care. Now my calculus teacher was a total dick, but he was my favorite teacher. The reason for this is because even though he was really mean, you could tell that he cared a lot.

So back to me being a shitty student, I fell asleep in his class. A LOT. My grade never suffered from it, and in fact I had an A in this particular class, but my teacher was (perfectly understandably) upset every time it happened. So as previously said, he's kind of a dick. So his way of solving this problem was to kinda pick on me, calling on me purposely if he could tell I was falling asleep/knew that I didn't know the answer, yelling at me in front of the class etc. (note that I think this is a perfectly fine reaction and in no way think it was unreasonable).

So this stuff goes on all year. I fall asleep/stop paying attention in his class, he yells at me/makes a fool of me to try and get me to stop, and then the last day of the year comes. The class dismisses and he asks me to stay after, I assume I'm going to be told the normal "you better shape up" type of stuff, and I was not prepared for the actual soft, caring teacher personality that I was about to witness.

He explains that he knows he's been really hard on me all year, and that he hopes I realize why that is. He then explains in detail that he sees me as an incredibly bright individual, and that I have the potential to be the type of person that can make a difference in things, etc. He then states that he' worried that I'm just going to throw away that potential by being lazy/uncaring about anything in general.

That probably seems like a really cliche thing for a teacher to say to a student, but here's why it affected me. I had always viewed myself as being a fairly capable person, but not a single person had ever SAID something like that to me. Something about it resonated with me, and I shaped the fuck up when I went to Purdue.

tldr: calculus teacher said something nice to me