Caffeine

There is only one word for my body's relationship to caffeine and that is WEIRD.

For the most part, I seem to have a reverse tolerance for it. When I'm drinking a lot of caffeinated beverages, it works in a very typical manner and I can predict my reaction to any given source of caffeine. I can even perceive some effect from tea. When I haven't been drinking much caffeine, I'm highly insensitive to it. I had a Red Bull at ten o'clock last night thinking "ok, playing with fire" but I still got tired as usual, went to bed normally and slept fine.

On the other hand, I used to notice a phenomenon where non-caffeinated sodas would give me a sugar "crash" and caffeinated ones didn't. When I started to drink more caffeine, caffeinated sodas started to be risky but energy drinks were still fine. That suggests ordinary tolerance, at least to that particular sugar-moderating effect.

My history with coffee confuses the issue even further. Or perhaps it doesn't. In any case, coffee will often actually make me sleepy - mostly in high doses. Why perhaps it doesn't confuse the caffeine issue is I've also observed this effect with decaf. This has ebbed and flowed - there was an instance where I started getting drowsy after half a mocha, but now I can easily have a regular cup of coffee with no problem.

So what in the hell is the pharmacology of all that?