I have just arrived back from a trip to Japan for further training in Shugendo. During mountain training we go through various trials that represent different negative states of mind and confused perceptions that test us in daily life. These include long treks in the mountains, days fasting, nights without sleep and daily sessions standing under freezing waterfalls or being exposed to chilli smoke in a confined space.
When we experience our own emotions and limitations under such extreme conditions we can overcome them to some degree and recalibrate our perceptions. When you have experienced extreme hunger or tiredness and return to the normal life you find your perception of hardship has radically changed.