Still and all why bother? Here's my answer. Many people need desperately to receive this message: I feel and think much as you do care about many of the things you care about although most people do not care about them. You are not alone.
I think that everyone at any age should ask themselves 'where do I want to be today where do I want to be tomorrow and where do I want to be in a hundred years?' We all have clear answers to those questions. We only have so much time. It's a real shame if we don't spend our lives trying to do that.
The answer to old age is to keep one's mind busy and to go on with one's life as if it were interminable. I always admired Chekhov for building a new house when he was dying of tuberculosis.