I divide failure into a few different categories. First is the scientific method of developing a hypothesis, testing, failing or succeeding in the test, re-evaluating said hypothesis (facts and assumptions) to take in test data, and repeating. There, failure is success in that it is helping with your perception of your beliefs/process/method/business model, etc. Another type of failure is the physical one. I think of this as finding your edge. Push your limits (range of motion, ability to move weight, balance, distance) towards their maximum, and then back off so that you can be in a safe space and improve your ability to do the task at hand. Edges change all the time, so I believe you have to constant be aware of where they are. Finally, we can have moral failures to live up to the standards that we set for ourselves or promise to love ones. As human beings, we make mistakes. It's learning from those failures that makes us better people, and to avoid them in the future.