From Nikola Tesla: “As suggested by the metaphor of mental pain being much like a limb ‘falling asleep ‘ when the nerve is compressed, the mind can actually carry a fair amount of pain of which it is imperfectly aware and thus chronic mental pain does not often manifest itself as pain in any particular way. Both under-stimulation and a certain degree of over-stimulation are normalized by the brain fairly readily in its drive to adapt to conditions; it is only when the effects of these factors interfere with too many other processes that the pain is noticed.
“This consideration is important: This adaptability allows you to continue dealing with immediate challenges yet at the same time every situation in which you put mental pain aside adds to the load the mind carries until the mind may collapse under the combined weight of little things, daily strains, and additional insults, provides the weight and leverage needed for mental, emotional or psychic breaks. This adaptability can also inure you gradually to untenable situations: much as the frog being boiled slowly does not react to its danger because it is focused upon adapting to the situation rather then to the situation. In short: you can become depressed; rigid or reactionary; prejudiced, biased or even bigoted; blase; sarcastic; contemptuous and supercilious so very gradually that you feel those actually painful thoughts are normal, when indeed they divorce you further and further from your native and natural capacity for unconditional love, happiness and joy.
“From this viewpoint, hidden mental pain warps your original mind into distressing shapes that provide triggers for you to lash out at others or yourself: as the mind follows the emotions so that when you are feeling uncertain, anxious, angry or despondent your already painful mind will look for reasons why you feel as you do, so also the emotions follow the thoughts: if the mind re-tracks the thoughts, “I’m bad,” or “You’re bad,” or “Life is bad,” then the feelings will follow, and how those feelings are expressed will be in accord with the shapes of your mental pain.”