I drink one large cup of regular coffee every morning. I've given up caffeine a few times and always go back to the one cup in the morning. I feel much more alert -- well, let's just say I feel alert, period -- and it even picks up my mood a little. Without it, I feel a little sluggish and slow.

Withdrawals for me are a bear -- bad headache, profound lethargy -- but only for a day. Hubby feels "a little tired" in the afternoon if he skips his coffee; that's hard for me to imagine.

Once, at work, I accidently brewed some decaf. The lids were switched on our coffee canisters. By 11:00 I could barely stay awake and was in full yawn-fest mode. I thought maybe I hadn't had enough coffee so I had a second mug. No difference. I barely made it through the day.... basically, the whole day was a total bust. The next morning, I noticed the switched lids! That's when I realized that I had gone through full-blown caffeine withdrawal at work. If I do it intentionally, it needs to be on a day off, with NOTHING to do that requires ANY concentration or level of alertness, keeping the aspirin handy.