If you climb to the summit of a mountain, you may stumble a few times. If you write a song you may erase a few words and replace them. If you paint a picture you may drip some paint.
On your way to accomplish any goal you may have a few mistakes. Do you let these mistakes stop you are do you keep going?
It all starts with your mindset and how you react to what happens. You must have self-descipline and belief to keep moving forward. You must keep the big picture in mind and the rewards of accomplishing your goals.