In regards to mistakes, failures, whatever you choose to call it. It's best to deal with it with the proper mindset. Yes, you produced an outcome other than the one you planned. Acknowledge it, own it. It's an experience that you can label as education. Learn from it, and don't create that outcome again.
So, let's say you've experienced a lot of education..... ok, you've earned a PhD from the University of Hard Knocks! :)