After a few years of running moderate distances, I ran a marathon in 2001. That day, after running 26 miles, I drank for 12 hours. Then I ate a dozen Krispy Kreme donuts. I refer to it as my triathlon. I was fine the next day and for a few weeks, then my knees started really complaining about the running addiction. My knees were fine with the beer and donuts.
I've slept four to six hours a night for nearly 20 years now. I drink three to six beers a day, but rarely at a rate greater than one per hour. I have two donuts every other day for breakfast. I got about 30 pounds heavier than I was when I was running 60 miles a week. I could do without it.
So, two years ago, I picked up cycling. After a year of riding my bike to work every day (15 miles round trip, morning donut stop included), I'd lost about 15 pounds. Then I got run over by a little old lady who ran a red light. She had a senior moment and didn't see the light, the half-dozen other stopped cars or the fully lit and reflective cyclist.
So, yeah yeah yeah ... take care of your body. Whatever. Shit happens.
I've never had any unique or interesting memory problems. I beat the 11-year-old neighbor kid on the Wii Fit stuff all the time; my Wii Fit age is usually almost half my actual age (37). In some ways, I remember much more than I used to. I have a little more trouble learning new things, but I learn them better and with more confidence. Maybe I'm just a better listener.