" From this day, you are no longer children. If you have to fight, even if it is a friend, put him down as fast and hard as you possibly can. Kill if you have to, or spare him—but beware putting any man in your debt. Of all things, that causes resentment. Any warrior who raises his fist to you must know he is gambling with his life and that he will lose. If you cannot win at first, take revenge if it is the last thing you do. You are traveling with men who respect only strength greater than theirs, men harder than themselves. Above everything else, they respect success. Remember it. "

― Conn Iggulden , Genghis: Lords of the Bow (Conqueror, #2)