If you hesitate even a bit, you will get eaten. Also, you have to be confident and motivated. I sang with Roberto Alagna when he was unknown, but I knew he'd be a star because he had drive. People think it was easy for him, but they forget that he used to work in a bar singing pop songs. Good singers will always be found.
Quality wins out over dishonesty and evil.
But if you are just after fame, forget it.