Right on, J.D.! I've heard "flow" explained a number of times before, but none as succinctly or inspirational as your post above.

As a fellow designer, I can't adequately describe the high I get when I'm "in that zone". It's something that doesn't happen often enough. But breaking down the steps into an objective model as you've done above will really go a long way towards helping me get into that state more often.