Ronda Del Boccio, Our official Storytelling Expert says:
Did you realize that you become the stories you most often tell yourself? Think about it. If you keep telling yourself that you're horrible at math, you will be horrible at math. Although there is a certain amount of native talent that you may or may not have, what you believe shapes who you become.
Read Ronda's entire article The Stories You Tell Yourself Shape Who You Become