Not succeeding at something that you put effort and energy into can be disheartening, disappointing and in some cases embarrassing. One thing is for sure it doesn't always feel good, well it never feels good. BUT like everything we do, it is all in how we look at it and when we change the way we look at failure and accept it as feedback: then we can identify what it meant, what we need stop doing and/or what we need to do better. EVERY time you think you have failed at something it IS a lesson for growth. And on a side note, never use the word criticism, it is one of those words that it doesn't matter how you frame it it causes a negative physical reaction when you hear it.