Cortisol — released by the adrenal glands during the stress response; stimulates the amygdala and inhibits the hippocampus. - Rick Hanson

To become happier, wiser, and more loving, sometimes you have to swim against ancient currents within your nervous system. For example, in some ways the three pillars of practice are unnatural: virtue restrains emotional reactions that worked well on the Serengeti, mindfulness decreases external vigilance, and wisdom cuts through beliefs that once helped us survive.

Through activating the parasympathetic nervous system (PNS), you prevent the stress-response system from reacting to its own reactions. This is one reason why the training for equanimity in contemplative settings involves considerable relaxation and tranquility.

Simply having useful, enjoyable experiences is not enough.