Equanimity can be characterized as a quality of mind that is impartial.
Imperturbability is the opposite of a reactive mind.
In the journey of accepting what is in our life and world, the idea of equanimity allows us to receive without preference.
The great way is not difficult for those that have no preferences.
A mind that is open, receptive & impartial has tremendous strength and ease.
-The Third Patriarch of Zen Verses on the Faith Mind