This is one of the most powerful quotes ever written. It summarizes the humanity’s only true challenge and obstacle to happiness. It represents the source of all pains and diseases: us being taken over by the mind. Everything else is just secondary. Everything else is only details. Negative thinking, destructive emotions; and deadly diseases, are all just the result; just the consequences of the mind taking over and leading our lives completely. While who we really are, our spirit, is in the background, going throughout life without even experiencing it.