I know it is hard when things don't go your way, especially if something was lost. I personality struggle with defeat but after going through a few of them myself I came to realize that life keeps going. That as long as I am alive I can always improve and be prepared for next time. It doesn't come to one that easily, but with a positive and optimistic attitude, one can learn to see the good between all the bad. The thing about being optimistic is that you start to see where things could have been better and the next time you are faced with a similar problem you can apply what you learned before. There is a quote that says that success is not built on success but failures. You want to fail so much to the point where you start failing at failing because you know of a lot of the ways you have failed before and choose a different approach. I first started to notice this when I took on a door to door job. It wasn't fun to be rejected or let go of a sale because I didn't know what to do. The more I did it though, the more I learned and eventually became very good at sales. I would highly recommend doing something similar. It's an easy way to learn how to deal with rejection and failure. At the end of the day it's all about numbers or better known as the law of averages. The more you do something the better you become as long as you try your hardest. Just know that no matter what it was, as long as you are alive, you can always come out winning in some way, shape or form.
Anyway guys, that is just a bit of how I interpret failure. I would highly suggest searching Jim Rohn on youtube as he has more amazing content.
Until next time!