"People do not lack strength; they lack will"
-- Victor Hugo
You always hear what people say, "you can do it." Because you must have to. Plenty of sportsman display these attitude as well as in the movies.
The original Karate Kid I, II, and III and amputated athletes who still competes are the best examples of making impossible possible. There is also the movie 46 Hours about an adventurous mountain climber who got caught between bid boulders of stones but his will kept him alive. He stayed in the pit for 46 hours waiting for someone to rescue him until he decided to amputate his arms inorder for him to be released from the stones.