Even if you don't win, you'll still gain.

Nacho counting the pay they got from their losses in boxing

Life is really sweet.  Whether we lose or win, it offers a reward.  Just look at Nacho.  He joins any boxing match of his town, not to win, but to gain.  He realizes that by joining any match, he gets to receive a pay even if he loses.  Together with his buddy, they seek for boxing matches because money awaits them there.

Seeing things in this perspective adds up courage to fight. :-)