Hopefully, I'm traveling the world doing medical missions or going on zany adventures, still married to the love of my life, and barring that, knocking boots with pretty young things in every port. Because I'll be the Cool Old Guy. Probably also training medical students and residents, so I'll be the Old Master while I'm at it. What other TV Tropes can I throw in here? I'd probably emphasize my scholarly pursuits (interest in history, philosophy, theology) over physical ones (martial arts, swordplay, scuba diving) due to entering the winter years, though I really doubt I'll ever be banged up enough to turn down getting into a scrap.
Oh hey, this basically describes those two old guys from Secondhand Lions--yeah, I wanna be those guys.
And Fluffy, your future cougarness disturbs me. Here's a fun joke: If you call an older woman going after young men a cougar, what do you call a really old woman going after young men? A sabertooth. <ba dum tish>