I 100% agree with this. Almost every successful person I can think of started out as a "failure" or at least had many failures.
Thomas Edison failed so many times before making the lightbulb.
Albert Einstein I think was kicked out of kindergarten.
Abraham Lincon was an unsuccessful politician before becoming a great U.S president.
Shakira was told by her choir teacher she sang horrible like a goat.
The list goes on and on but something all these people have in common is they started out on a "rocky start" in whatever it was they were trying to do, but they kept improving and not giving up. and they did/ have done some amazing things.