I'm not so sure as I'd actually want to live to be an old man. As far as I can tell, old age is basically an exercise in controlled disintegration. I mean, biologically speaking, the human body is at its peak somewhere between 25 and 30. So by the time you're double that age things are really going to start getting run-down and worn out. Plus I'd prefer to die in an anecdote (my current favourite is a runaway airship incident)as opposed to staggering into my body's expiry date.
If I did find myself at an autumnal age, I would sport an exquisite moustache, waxed into finely tapering ends (I'm thinking along the lines of Edward Drinker Cope); a fine pipe filled with nothing but the best tobacco and I would berate anyone who would listen -and a good few more besides- with Abe Simpson-style senile ramblings.