No. I've become very physically aware of how caffeine borrows from my body's resources. There's always a need to recover later. After all, there was a reason my energy wasn't that high in the first place! So that reason comes home to roost.
I also suspect I adapt to caffeine faster than average. I think I get a little dependent. My body growing a few more adenosine receptors. So the next day or two it has to notice that those aren't needed.
But I think I'm just super aware of these energy fluctuations. Mostly because I trained my awareness to be this fine-tuned. I doubt I would have noticed the effects I'm talking about five years ago.
You are correct. There was a sign error that I didnt notice because the answer looked so similar to the one I knew was right from doing it before Thanks! It is corrected now
what is this cost? Are you talking about late caffeine drinking disrupting your sleep?