It's not failure, it's learning.  We tend to learn more from a failure than a success because of how our biology has evolved over time; maybe 4 - 6 times more.  But this learning is only open to those who are interested in extracting the lessons from the experience and applying it on the next attempt.  Unless another attempt is made in which the learnings from the last try are incorporated, there is no real learning; there may be understanding but no real learning.  Accomplishment is an outcome of failure; not the absence of it.  And to accelerate the learning to achieve the accomplishment requires us to fail well where we extract the key lessons learned and insert them into the next attempt.  Do not fear failure, or avoid frustration as they are both required for the accomplishment of your greatest goals.

There is no failure. Only feedback.  Robert Allen

Don't worry about failures, worry about the chances you miss when you don't even try.  Jack Canfield

There is but one cause of human failure and that is a man’s lack of faith in his true self. William James