Why does caffeine have no effect on me?

In My Humble Opinion
1

I can drink three mugs of very strong coffee… and then go to sleep. It doesn’t keep me awake or make me jittery. The only effect I’ve ever felt was when I hadn’t had any for a few years. The first cup kinda perked me up. But after that, nothing. And the caffeine in some soda has the same non-effect.

I do have intense insomnia. But that’s a constant, with or without caffeine.

2

It’s just after 3AM and I’m right there with you. Maybe we just have superior genes that on the one hand make us immune to caffeine’s deleterious effects, and on the other provide us with the stamina to stay up all night?

I think I’ll have another Coke Zero while I ponder that one…