Have you ever come across anyone who has never failed at anything? All people make mistakes and fail at something. If they did not fail, they could not have learned the skills which subsequently made them successful. One learns through trial and success.
Why are we so sensitive to our ‘failures’? It probably has a great deal to do with our self-image. We do not want to be failures in the eyes of others, especially if we value their opinion.
Whenever you want to say, “If only…” change it to “Next time…”.