It's a weird thing though ... now that I'm 35 I definitely can't bang out work until 3am like I used to 10 years ago. On the other hand, I have significantly more knowledge and better methods than I did then.
Youth is wasted on the young - my new favourite saying.
Somehow a young person has to work out a way to hack the process, by gaining wisdom and maturity before their youth has run out, and apply it successfully. (and, to be fair, 35 is still young). To be more correct, someone in their 20's need to work out how to think like someone in their 30's or 40's, before they turn 30. Young people who do that are going to be successful, no doubt. The big problem is that a 20 year old has to listen to, and accept advice from, a 40 year, something many have problems with.
Getting the young to have the experiences of the older and wiser is never going to happen. It is more productive to retain or regain whatever you consider the value of being young into old age. Personally, except for some aches and pains in my joints, I haven't noticed any real decrease in any of my abilities as I have gotten older.
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.
I'm the same... I'm 29 and have a new-born, I really struggle to make it through the day without a nap these days.
When I was 22, I could easily get up at 8am, and work till 4am five days a week, then go out and hammer it at night clubs until the wee hours at the weekend with a bit of a rest on Sunday.
I can bang out work much faster, more professionally and downright efficiently than I ever could at 20. I'm 39 and I can, and do, run rings around kids right out of college.
I always have an answer for people who try to act like putting in long hours makes them a better employee, or more dedicated, "if you can't get your work done, give it to me and I'll do it, and still leave on time every day. Then they can cut your salary and give half of it to me."
It's a bit unfair.