A quote from Robert Heinlein's book, Time Enough For Love:
The way to live a long time — oh, a thousand years or more — is something between the way a child does it and the way a mature man does it. Give the future enough thought to be ready for it — but don't worry about it. Live each day as if you were to die next sunrise. Then face each sunrise as a fresh creation and live for it, joyously. And never think about the past. No regrets, ever.
Don't mind me, I'm just going to sit here and contemplate that paragraph for a little while. You go on. I'll be fine, honest.