You don't live for others. I think you live for yourself. And learning and doing something good is a way to make life more pleasant, rather than living in a void, doing nothing, feeling nothing.
To me, life may be a shadow, without light, there is no shadow. Or am I wrong?
What you do with your life is up to you. Just make sure that you don't regret it. I believe there is just one life to live, and that we must not waste the time we were given. And if we have some power, some skill or talent, we should use it.
But then again, this is my opinion, which may differ from yours.