[PancakeBrah]

Or you've just built a tolerance.

I stopped drinking coffee for awhile. Not purposefully. I just kind of forget to drink it, I guess. Lasted for a few months. Then I remembered I drink coffee. Drank a few cups and was absolutely wired. A little jittery, like some people have said. That lasted a few days. Then my tolerance returned and I can drink coffee @ 8 P.M. and fall asleep a few hours later.

Try going a couple of weeks without coffee or energy drinks then jump back in. You'll see it's not a placebo effect. Although with your level of consumption you might experience withdrawals and once you return your body will just return to the state it's used to.