Some of this is just aging, though. When younger, I could do all nighters regularly and bounce back quickly. Can’t do it any more without, as you say, nosebleed interest.
The harsh reality. Many of the lifestyle habits simply become exponentially harder as we age.
i watch my kids bounce back from and fight through illness in awe. My wife says i suffer from "man colds" but when i have a fever i'm completely incapacitated. I just lie in bed and think "... so this is how it ends" heh