evidence: Muhammad Ali was as skilled with words as he was in the ring. His poignant sayings about sports and life figure to remain iconic for generations to come alongside the lore of his historic fights. [...] Impossible is not a fact. It's an opinion. Impossible is potential. Impossible is temporary. Impossible is nothing." Why we love it: This quote often is truncated to the last part "Impossible is nothing." But the rest means so much more. While many will immediately deem a goal impossible, for the right type of person, that doubt leads to untold motivation.