I heard an educator say once that if you're getting all A's the work is likely not difficult enough for you. In the course of learning something new there is a process. We do not reach this being part of our knowledge base until we have worked for it. It does not matter if we are talking about Physics, Home Ec or riding a bike. We are not supposed to be instant learners. It is only through "failure" that we grow. Especially when we are in school or "trying out" for something we think if we don't get an A or we did not get the part or whatever we failed.
We only fail when we fail to try or fail to do our work. Yes these other things feel like failures. In addition to telling our kids about times thing did not work out for us we need to tell them about times we tried but just didn't come out on top. The only real failure if not trying.