Thanks for your speculation as to what the nature of this effect might be, but I don't need it. Unless you totally abstain from coffee, tea and fizzy drinks, you have no idea what caffeine is like after not consuming it.
Especially, seeing as another guy here speculates that taking a nap after drinking coffee is a caffeine effect on ADHD, perhaps you two might want to speculate against each other as to whose speculation is more correct, speculatively speaking.