Why work hard?

Everyone keeps telling me to work hard, get a good job, start a family and retire when I’m old. I understand why, it benefits society to have hardworking people, but why should I care. Why not just stay at home, do drugs, watch movies, watch porn or play video games and waste away if I get the same amount of happiness. I don’t care about the long term effects, I don’t want to grow old. I don’t want to live to the point where I’m just waiting for death. I’m currently 15, I go to the gym, I study and get good grades, I eat healthy. Yet I still don’t feel happiness, like I’m just waiting for a reason to try. And I do want a reason, I want to know if there is a future that would be worth all the hard work.