Drug metabolism is often better modeled by two (or sometimes more) different half-lifes for different stages of metabolism. So typically plasma concentration will diminish quickly but be followed by a long tail. In the case of caffeine I think this is due to enzymatic saturation.

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.

I used to be able to do this - take a double espresso, wait an hour, and sleep through the night. But as I've gone through my 40's, insomnia's been a problem.

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.

sleep through the night is not the same as quality sleep. Just like after drinking alcohol many people can fall asleep, but it blocks REM(?) sleep.

So, while you might sleep all night. It's low quality sleep.

I've drank my first coffee of the day and immediately suffered an intense desire to nap. Coffee just isn't a very intense tool for the job.

I've read that one of the symptoms of ADD is the reaction to stimulants. Specifically, they tend to have a calming effect instead of the typical jolt of awareness.

Oh, that would explain so, so much.

Yeah me too. Occasionally I get clarity but rarely energy. The warm soothing drink makes me sleepy.

Raw coffee or did you have sugar/cream/whipped cream in your coffee?

I'm not the parent, but I drink light or light-medium roast coffee only, black, and I can take a nap (edit: or just go to bed for the night!) any time after it with no problems. The only thing caffeinated coffee does for me at this point is make me poop and keep me from blinding headaches.

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.

Im just like you minus the headaches. I could drink coffee and nap right after and the morning jolt is a learned experience since decaf and non decaf has the same effect. I drink coffee to enjoy its taste manly. Acutally i used to drink 5 coffees a day and at the 5th i’d feel the unpleasant jitter in my body so cafeine does seem to have an effect in large quantities but I could still nap in those conditions as well

I feel that, I've gone through entire pots by myself before and that's when I started seeing colors and smelling shapes (not really, but it was a distinctly disorienting and uncomfortable experience). I tend to limit myself to 2 cups a day since I know I do have a caffeine dependence and I don't want to spend the entire day strengthening that - it would mean EVERY day would have to be like that, and I don't want to be that much a slave to my bodies caffeine requirements for a baseline, you know?

But sometimes, when no one is looking? I make a third cup.

this is me. ritual induced learned responses aside, keeping "regular" is the only noticeable outcome from drinking coffee. but I very much enjoy the taste -- the lighter and funkier the better. I'm ADD inattentive, as are some of my kids. Kid's doctor actually suggested we start giving black coffee to one and I kinda got excited to introduce the ritual to them.

I'm struggling with this myself, both for myself and for one of my kids and I'll try the tea trick on the kid right away :-)