So... what is a 'flow-state?'

This is a term created by a brilliant Psychologist Dr Csikszentmihalyi. "A state of effortless concentration so deep that they lose their sense of time, sense of themselves, sense of their troubles..." It is a joyous state of Mind we can all experience from painting, dancing, reading, riding a motorcycle or doing something like mathematics. In this flow state our Brain very neatly separates the two forms of effort: attention control and concentration on the task. As such maintaining focused attention seems effortless which in-turn frees up more brain resource for the task at hand. 

Try to be a little more aware of what enables you to enter a flow state today, breathe and relax and then enjoy the experience.