Why don't people realize that they might as well try in school considering they have to go anyways?

Kids everywhere act like school is a waste of time and say that they don't learn anything all the time. They just don't seem to try unlike me and some other students. I realize I won't use half the stuff that I learn but I also realize that it would be a waste of my time to go to school 7 hours a day 10 months a year for 12 years and not spend that time at least paying attention. I notice that the ones that don't try are the ones who complain the most and don't know how to think for themselves. But I also realize that some of the ones who pay attention too much and sort of take it too seriously as if it is a matter of life and death.