The people in a village on the Niger River in Africa were losing fellow villagers at such a rapid rate that they had to call in the Army to hunt down the culprit: a 22-foot, 2,500-pound crocodile.
Introverts shut down when they're going through shit. They want no sympathy. No advice. No trying to "fix" them. All they want is silence and solitude. They know how to pull themselves out. Just leave them alone for a while.