" Gradually, methodically, he shed most of his anxiety. But not all. Being too relaxed, he felt, was also a danger. In appropriate doses, worry was useful, possibly lifesaving. “I used worry to encourage thought,” he said. “Worry can give you an extra prod to survive and plan. And I had to plan. "

― Michael Finkel , The Stranger in the Woods: The Extraordinary Story of the Last True Hermit