Diminishing Cognition

There was a point in my life, as I’m sure there is in everyone’s lives, where I perpetually sought out self-destructive pastimes. I would smoke excessively, drink mass amounts of alcohol and caffeine, and stay up for days on end.
When I did sleep it would be in strange and awkward places. I would park my car in an abandoned lot, that I hoped no one would bother with, and take a nap. Sometimes I would have the opportunity to crash on a couch, or in a lounge, or at least sleep in a stairwell using my knapsack as a pillow.
Needless to say I developed a crick in my neck and dark circles under my eyes, which had managed to develop a reddish tawny color from the eyestrain and build up of bilirubin in my blood.
My complexion was a pale and sallow outer coating of skin fitted over muscles that were clearly suffering from a lack of proper nutrition, which, contrary to my belief at the time, could not be derived from the investment of $.75 into a vending machine every few hours.
In my youthful inanity I would wear my ailments as something that had been achieved successfully. They displayed that I had the upper hand in my body’s struggle to stay alive and in good condition.
Somewhere something changed. I started to exercise regularly, I quit everything but caffeine, I got a haircut, but I can’t remember what triggered it.
Perhaps it was from reading articles about how my body will steadily decline well enough on its own without my assistance in the matter thank you very much.
The bad news is the “notable decline in certain measures of abstract reasoning, brain speed and in puzzle-solving" becoming apparent at 27.
The good news is “vocabulary and general knowledge, actually increase at least until the age of 60.”
After one begins the inevitable decline, what is there to look forward to?
So far all I have found is that by the time I reach 60, and can no longer learn new words, my body will have eased itself out of its current caffeine addiction.
This does me no good, as I enjoy coffee too much and will continue to drink it with flagrant abandon.