Marcus Aurelius asks, “Are you surprised to find a fig tree bearing figs?” By this he means that all people act according to their shared human nature. But just as there are varieties of figs, so too there are varieties of humans. This one is patient; that one is not. This one is focussed and driven; that one is not.
You deal with young people. Is there a more bizarre population in the world? How then can you be upset when a boy of fifteen does the things a boy that age typically does? He is merely acting in the ways that his variety of fig acts. Accept him. Do not be angry. And show him a better way by your own actions.