Flow

A desirable mental state.
- "In positive psychology, a flow state, also known colloquially as being in the zone, is the mental state in which a person performing some activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by the complete absorption in what one does, and a resulting transformation in one's sense of time."
[go] https://en.wikipedia.org/wiki/Flow_(psychology)
As defined by Mihaly Csikszentmihalyi (I can never remember his name).