But a non depressed person would just call that growing pains.
Remember the old line, we learn more from our mistakes than we do from our successes.
Anyway, I know what failure is, but in reality, it's just a plateau on our way up. Because if we look at it in a linear fashion, even when we think we've failed we are usually still farther ahead than we were a month, or a year ago.
I remember when I was starting out in photography I would see someone's work and think, man, I'm nowhere near that good. But the beauty of it is you can wake up the next morning and start to go after it again.