[gwbas1c]

Caffeine just made me act like a coke-head. Remember, cocaine's effects are very similar to caffeine.

I also used to get bad insomnia from caffeine.

That's why I switched to decaf in the morning.

As far as a productivity shift... That's hard to quantify. It's easy to get under the influence of a dopamine boost and fool yourself into thinking you're more productive; when you're really making more mistakes and driving your colleagues nuts.