This is one of the times something made sense because someone was better at me at expressing something I had independently (perhaps almost) concluded and experienced for myself.
The talk is about achieving or being in flow. I sometimes achieve it when writing, it happened to me during an aikido grading where I was feeling invincible while being thrown around continuously, sometimes even when doing lab work with a protocol I have mastered and trying to beat my previous record.
Now that I know about it, I can consciously strive to achieve being in flow more often.
According to the talk, you achieve flow when you strike a balance between being too aroused, if the task is too challenging, and being in control, if you are more skilled than the task requires.
In more detail, the speaker defines the state of flow through the following simultaneous achievements:
Focus - complete involvement, concentration
Ecstasy - being outside everyday reality (perhaps because you run out of sufficient brainpower to support experiencing the everyday reality!)
Clarity - knowing what needs to be done and how well you are doing
Confidence - knowing the task is doable and you are adequate
Serenity - peace with yourself, growing beyond boundaries of ego
Timelessness - hours seem to pass like minutes due to focus on the present
Intrinsic motivation - whatever produces flow becomes its own award
Needless to say I find the video well worth of your time.