Robert Greene said this quote
“ Understand: your mind is weaker than your emotions. But you become aware of this weakness only in moments of adversity--precisely the time whenyou need strength. What best equips you to cope with tthe heat of battle is neither more knowledge nor moreintellect. What makes your mind stronger, and moreable to control your emotions, is internal disciplineand toughness.No one can teach you this skill; you cannot learn it by reading about it. Like any discipline, it can come only through practice, experience, even a little suffering. ”