Failure is so important. We speak about success all the time. It is the ability to resist failure or use failure that often leads to greater success. I've met people who don't want to try for fear of failing.
J. K. RowlingWhat was there to be gained by fighting the most evil wizard who has ever existed?" said Black, with a terrible fury in his face. "Only innocent lives, Peter!" "You don't understand!" whined Pettigrew. "He would have killed me, Sirius!" "THEN YOU SHOULD HAVE DIED!" roared Black. "DIED RATHER THAN BETRAY YOUR FRIENDS, AS WE WOULD HAVE DONE FOR YOU!
J. K. Rowling