I'm 49 and I have less trouble staying up late or even working around the clock than I did in my twenties. I think a lot of the age-related difference is just

I'm 49 and I have less trouble staying up late or even working around the clock than I did in my twenties. I think a lot of the age-related difference is just opportunity and desire. Do to a combination of traveling and working in April of 2005, it happened that I ended up staying awake for 40 hours, I was a bit flaky by the time I got to sleep it out, but could have stayed up longer if I had needed to.