I'm puzzled whenever people say things such as, "I have a high tolerance for pain." How would you ever know whether your "tolerance" for pain were actually a form of insensitivity? In other words, what's the (externally observable) difference between being able to tolerate or endure pain and simply not *feeling* pain? Maybe that guy who seems admirably tough and strong-willed actually just lacks the capacity for really powerful sensations. We talk almost as though there are two parts of a person: one part which feels the pain, and another which resists.