Supposedly, the number of adenosine receptors in your brain increases over time with caffeine consumption, creating a tolerance to caffeine.

I've read articles [1] which suggest that cycling off caffeine for 7-12 days helps reset the number of adenosine receptors to the baseline.

[1] http://www.smithsonianmag.com/science-nature/this-is-how-you...

I go cold-turkey every once in a while. I've just come off a 12-day abstinence, which was prompted by an eyelid twitch that I couldn't get rid off with simple sleep. Dropping caffeine did the trick.

The best part is the first morning coffee after a long abstinence: you feel wired, motivated and productive like you've never been before.

My observations seem to differ. Every now and then I slip into increasing my dose. But, for 90% of the time I drink one shot of espresso in the morning. It keeps me alert for most of the day. When I feel a bit bored or lazy after lunch, I'd have another one. If I keep doing that for a week, I realise the days when I don't I get particularly sleepy and low energy. 3 days after sticking to morning coffee only reverts me back to previous energy levels. I'd say if you are disciplined with your dose, it helps just the same as it did when you started drinking it.