A couple of observations from when I quit coffee (after being only a pretty mild drinker):

- I'd still get the feeling of "oh shit it's 4pm and I've not really started doing anything productive today". But then I'd look at the clock and it would be 10am and it turns out I still have the whole day ahead of me. The day passes so much slower that, even if it feels like your pace of work is a bit slower, you still get much more done overall.

- I'd get to sleep much faster (measurably because I would fall asleep before my partner, having previously got to sleep reliably after her). That applied even compared to days where I'd have coffee only before lunchtime. The idea that late-day tiredness from caffeine withdrawal helps get you to sleep is nonsense.

Having said that, I've relapsed back to a few cups a day. Logically I know I need to quit again.