I do a coffee detox every Sunday, and can tell you that the brainfog and lethargy is real. In my case, it's 2-3 cups a day Mon-Sat for this effect to occur on Sunday.
If I limit myself to 1 cup of coffee a day, and do the Sunday detox I just generally feel irritable and eat more sweet things to compensate but without any headaches
It's exactly where my control key used to be, so I often hit that button and nothing happens, unless Im using a Windows via AWS and suddenly I keep getting copilot springing up.
It's a really user hostile move knowing that people will accidentally hit that button
I love this