Until recently I was drinking caffeine as though it was a life requirement of the air or water magnitude. I definitely felt the low if I didn’t have it after a while, and I needed to be at or near peak performance to get my work accomplished at the level I like to operate at. Recently, I discovered just through trial and error a few of the things mentioned in this article about concentration in the section about Concentration and Your Body. I have one cup of coffee in the morning first thing, and a big tumbler of water along with it, and then I stick to water the entire rest of the day – no soda, coffee, or other caffeine or sugar sources. And now that the weather is getting nicer in Phoenix (under 100 degrees at noon), I’m spending my breaks at work out in the courtyard by a fountain, just smiling and thinking about the day, breathing in the fresh air for a bit. I definitely feel significantly sharper these last several days than I have in quite a while.