I'd still like to learn more about how others experience what has been in Paul Graham's text and what I myself described. I mentioned possible lack of dopamine, but I could also add after-effects of jogging (I rarely code anything before doing such, because I think so much better after aerobic exercise).
Generally speaking, I'd like to learn why it could (sometimes) happen that mentioned "withdrawing" process starts too early and happens too quickly. It has a lot to do with different biological systems (circulatory system, endocrine system, nervous system, etc.).
I disagree. That's obviously preference. I would find this sort of question odd on Stack Exchange (I go there specifically for technical answers to technical questions) and I don't ever use Quora.
Paul Graham wrote an essay on it (http://www.paulgraham.com/head.html) which I'd suggest you give a try.
As a meta-note... these kinds of questions probably belong more in Quora or Stack Exchange than on HN.