How much caffeine is too much?

I’ve been having trouble sleeping lately. I know people who brag about how they can function just fine on five hours of sleep. Not me. No way. No how. Seven works. Eight is better. Five stinks. Four, well, that’s just unbearable.

So I grabbed a mocha this morning. Then I drank two cups of green tea. And I just ventured down to the vending machine and snagged a 20-oz. Diet Coke.

Do you think that will help perk me up? Please say yes.