Flow is a state in which your mind is so completely focused on a task that your external awareness of the world is essentially shut off. This is the optimal state for “getting stuff done”. But, as I suspect most creatives already know, it’s not the optimal state for coming up with new ideas. That state is the opposite one – one in which the mind is *unfocused* and idle (not unfocused because it’s too busy jumping around). The key to being an innovative individual, one who can both create and do, is having very fine control over your focus – knowing how to cultivate both creative and flow states at need.

http://io9.com/5933423/the-right-way-and-wrong-way-to-let-your-mind-wander