I seem to be a slower cyclist without a brake. I pay the same attention but I dont feel less safe with a front brake... but I do pedal downhills much faster regardless of the stop expected at the bottom. I just know I can stop faster and easier so I go faster... its a lie when people say they can stop as easy or as fast without a brake.
I think ZEN is achieved when paying very little attention. it's what you feel the moment before hitting a car haha.