At what point do you lose rapport?

As a teacher who wants to be cool, I worry about this sort of thing. Negative feedback kills me, causes me to stew for days. One kid recently wrote on a reflection that I "talk in circles." Of course, it was on a final that he was taking early because he was on his way to Florida. His mindset again vs. mine: he wants to get the thing done and get out of there and I'm asking him a self-serving question on the final, asking him to rate me as a teacher. He doesn't care about rating me. He wants to get his points on the final and get out. Bad rapport move, but I paid for it with a jab at my skills. Fact is my skills probably had little to do with his response. Adolescent spych again. What motivates them? Themselves. They motivate themselves. Mostly, their immediate needs motivate them

How would this need for immediate gratification manifest itself in the classroom? Eating. texting. socializing while they should be focused on something else. Getting excited about the girl or guy next to them...Are these impressions corroborated by research in adolescent psych?

I may need to take a class, or at least read a textbook.

Brain rearach will have to be a part of the book.

Interview psychologists.