They say hours in the library can save years in the lab. I read a long, long time ago about experiments regarding human perception of time show it to be fairly steady in the present, but when you are recalling the past its rate of passage is determined by novel memories.
Which makes sense when you think about it - it's not like we have a time clock in our heads, the only way we have to judge time is unique memories. And as you age, fewer and fewer things are novel to you, so time seems to be passing faster when you think about the past.
Do something new as often as you can and you'll feel like you're living longer. Try to make those new things good experiences, and you'll feel like you're living a longer good life. You might as well, after all once you have food and shelter taken care of what else is there to do with a life anyway?