[vidarh]

I think the issue is how you'd find enough people sufficiently "clean" that 66mg-100mg would be a big dose. Most people don't keep track of their caffeine ingestion at all, but downs big cups of coffee at uncontrolled intervals.

For my part withdrawal from going cold turkey is absolute hell unless I'm travelling or otherwise majorly changing my routine. Like with many other drugs, despite the severe physical effects, caffeine withdrawal is very dependent on mental state as well. I always tends to minimize or totally stop my caffeine intake when I go on holiday or visit family etc, and I don't notice any of the normal withdrawal effects.

If I for whatever reason want to "reset" outside of travel, I'll try to step down, and pre-emptively take a paracetamol/acetaminophen early evening because I tend to start getting shakes in the evening if I reduce my caffeine intake too quickly. Cold turkey is too brutal for me.

People don't seem to realise just how much caffeine can affect them. It can be incredibly useful, but like you I find it weird that people consume it ad hoc without carefully managing the doses. I suspect a lot of people spend a lot of time miserable without realising why because of it.