Once upon a time there was a stupid teenage boy... He had a mom who didn't care whether he lived or died, as long as she left him alone... An evil ste father who liked to beat him, and two brothers who he was always in trouble with, because everything they did wrong earned him a beating. The two brothers took delight in doing whatever they wanted, knowing that they did not have to suffer any punishments.
The stupid teenage boy, decided, stupidly, that he would just coast through school and never once cared about his grades or learning. The argument he used when asked, not that anyone cared enough to ask, was that if no one cared, why should he?
See, stupid.
Don't be that teenage boy! Now he is 55, looking back on so many wasted years, regretful. You do not want to be me.