If asked to name a genius, most people would come up with the name Albert Einstein. Yet even for Einstein genius did not come easy. He had speech difficulties as a child and was once even thought to be mentally handicapped.
As a teen he rebelled against his schools reliance on rote learning and failed. He tried to test into Zurich Polytechnic, but failed again (although he did very well in the math and physics section…as you might expect). Einstein buckled down, received the requisite training and applied to Zurich Polytechnic again, and of course was accepted.
A few years later he had a PHD and was recognized as a leading theorist. A few years after that he had a Nobel prize for physics and began to be recognized as the genius of our modern era.