Why do you think you will "fail"?
What is so wrong about "failing", anyway?
It's an opportunity to learn, to progress, to improve.
If you don't try, you will never know.
Others may mock, but you have achieved, while they have not. You have learned, you have progressed, you have improved.
What have they done?
Isn't it better to aim high and fall short than to aim low and hit the target?