It is a great documentary about animals, social animals: The human species.

A strong talk with sentences like:

“Our jobs are killing us…”
“Leadership is not a rank, Leadership is not a position, Leadership is a decision, Leadership is a choice, […], Leadership is a willingness to sacrifice a little for someone”

Mr Sinek on the chemistry of human behavior – Endorphin, Dopamine, Serotonin, Oxytocin, and “Cortisone with a big C”.
Leaders will take some notes. It’s not about management here, it’s about leadership (Remember: Management and leadership are complementary, they should not be opposed).
It is linking our “bioself” to our work environment.

Unfortunately, pretty convincing.