Well I liked the song – and the Beatles - although I thought it didn't apply to me.
When I'm 64 years? YHGTBSM!
I always figured to die young and thus leave a good-looking corpse. But alas fate prevailed.
Like Mickey Mantle said: "If I knew I was going to live so long, I would have taken better care of myself." I had no idea.
Life is a poker game. I drew a pretty good hand, played it well, and had some amazing luck to boot. Life is sweet, and sometimes great revenge. Protect it, cherish it, but don't worry about it too much. Live, fight, love, and make a bit of a difference.