Flow is the mental state of operation in which the person is fully immersed in what he or she is doing by a feeling of energized focus, full involvement, and success in the process of the activity. Proposed by positive psychologist Mihály Csíkszentmihályi, the concept has been widely referenced across a variety of fields.
Colloquial terms for this or similar mental states include: to be on the ball, in the zone, or in the groove.
And suddenly I realised that I was no longer driving the car consciously. I was driving it by a kind of instinct, only I was in a different dimension. It was like I was in a tunnel. Not only the tunnel under the hotel but the whole circuit was a tunnel. I was just going and going, more and more and more and more. I was way over the limit but still able to find even more."