“The mind is something really important. It can kill you or it can get you out of danger. We can see this from wild animals that we tame. Wild chickens, for instance, are really afraid of people. If you pounce on one and hold it to have a good look at it, it’ll die. What killed it? The fierceness of its mind killed it. If it’s afraid, it can be so afraid that it dies. Just like people: When we get sad, the tears will flow. When we get too happy, the tears will flow—because the mind doesn’t stay in a condition that’s just right.”