Flow

n. a state of optimal experience arising from intense involvement in an activity that is enjoyable, such as playing a sport, performing a musical passage, or writing a creative piece. Flow arises when one’s skills are fully utilized yet equal to the demands of the task, intrinsic motivation is at a peak, one loses self-consciousness and temporal awareness, and one has a sense of total control, effortlessness, and complete concentration on the immediate situation (the here and now).

— Mihaly Csikszentmihalyi —