Did you feel like your intelligence was defined by how you tested or your grades as a kid. Maybe you got a terrible grade in math and that fixed your understanding on how good you were in that subject. It would also not be surprising if some of the fixed mindset that was developed in you at a young age continued to carry over to your career. With method, training, and patients I think you'll find yourself amazed by what you can become with the right mindset. Push yourself to learn and grow a little bit more everyday.

This comes from one of my favorite books "mindset" by Carol Dweck.