He called it a "flow state." This is when you are so absorbed in what you are doing that you lose all sense of yourself, and time seems to fall away, and you are flowing into the experience itself. It is the deepest form of focus and attention that we know of. When he began to explain to people what a flow state is and asked if they had ever experienced something like it, 85 percent of them recognized and remembered at least one time they'd felt this way and they often said these moments were the highlights of their lives. It didn't matter if they got there by performing brain surgery or strumming the guitar or making great bagels- they described their flow states with wonder.

— Stolen Focus by Johann Hari (Page 55)