Everyone knows a story about someone who failed enough times to become a success. The more times a person fails, the closer they come to that moment of "eureka". No one is born with honed skills or talents. Only training or education applied will lead to accomplishment.
Hearing someone say "You could never do that" reveals more about the speaker than the person receiving the negative advice. The best "revenge" for such guidance is to prove the person wrong. Receive the training or education required to accomplish your goal, and then apply the knowledge toward reaching that goal.
Learn from mistakes. (One definition of insanity is repeating the same action over and over and expecting different results.) When something doesn't work, change the experiment. We've learned that from Thomas Edison who "succeeded" 1000 times to prove something didn't work so he could then succeed in discovering what did work.
Let there be light!
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