You’re completely involved in what you’re doing: you’re completely focused and concentrated.
There’s a sense of ecstasy–of being outside of everyday reality.
There’s a great inner clarity: you know what needs to be done and you get immediate feedback on how well you’re doing.
You know that the activity is doable, that you have the necessary skills to complete the task successfully.
You lose your sense of self and all of your worries and concerns drift away.
You lose track of time and you’re completely focused on the present moment.
There’s an intrinsic motivation—whatever produces flow becomes it’s own reward.
Interestingly enough, the idea of flow came into being as result of research on happiness. Researchers began asking themselves: “What makes us happy?” and “When are we most happy”? As a result of this research psychologists realised that being able to enter the flow state–which is a very enjoyable experience–is a key component of happiness.