When your subjective experience is altered as you become absorbed or fully immersed in your activity
The experience of Flow includes…
1)A loss of the feeling of self-consciousness, attention is directed outwards towards their activity.
2)Distorted sense of time, one's subjective experience of time is altered as people become absorbed in their activity.
3) A sense of personal control over the situation or activity.
4)The activity is intrinsically rewarding, so there is an effortlessness stream of action.