It seems that this second half-life must be the difference for people who have more trouble sleeping long after caffeine intake. I wonder if this implies that their bodies have different maximum attainable amounts for the proper enzyme. I'm curious if anyone knows more detail about how the interplay between enzymatic saturation and genetics / gene expression works here.
Further, Pollan's interview suggested that even if I could sleep, caffeine was interfering with "deep wave sleep" - so I gave it a shot. I consider myself lucky that none of the headaches or [extra] irritability kicked in, so there's that.
So, while you might sleep all night. It's low quality sleep.
I think the awake/alert factor I get from having my morning coffee at this point is a learned response, not a chemical one; a decaf coffee is just as good at perking me up in the morning as a non-decaf. If it weren't for the headache spikes hurled straight through my brain by satan himself I wouldn't even bother.
Edit: That's not true, I actually do love the taste and ritual of making coffee too; it's a whole thing to me. It's like a Japanese tea ceremony, but with coffee.
But sometimes, when no one is looking? I make a third cup.
Here is the link to that interview for anyone interested: https://www.npr.org/sections/health-shots/2020/02/10/8033940...
But the best sleep by far has been the last month, when I've reduce alcohol to 0 for 6 nights a week, just once on the weekend.
Using AutoSleep on Apple Watch you can see the insane differences. My deep sleep is often over 2 hours, which is when I literally feel like my brain has been rinsed. Got 4 hours of deep sleep last night which is a bit high.
When tracking on nights after alcohol, deep sleep is often just 15-30 minutes. Focus is all out of whack the next day after alcohol too.
Interestingly, if drinking during the day and I stop drinking alcohol by like 5pm (day drinking) such as on the weekend, the impact is not nearly as bad.
With SleepCycle I only used it 10% of the days because I had to consciously choose to turn it on!