Disappointment is a great place to explore for new ideas; don't like that dish you got? experiment and improve on it till you get to what YOU like. Hear a song that is just a little off? perform it yourself until you get it the way you imagine it should be played.
the only way to get things done the right way is to experience error and disappointment. That is how I get things done, I have been disappointed many times, sometimes my fault and sometimes through the fault of others but one thing that remained consistant is that I always got up and either changed it completely or improved upon it, either way I was the better person for it.
A friend at work this morning honestly asked if success was the only criterion for giving good advice.
"Absolutely not!" I exclaimed. "Failure is just as necessary as success. Without failure there can be no learning. Without failure there is no impetuous to improve."
Failure is a big blinking arrow of places you can improve.
Also, I'm not 100% sure humans are capable of original thought, and the only way new things are invented/discovered, is we fail at doing something, and the result of that failure is the new invention. So the more you can fail, the more chances you have have discovering something new.