Remind yourself regularly: You’re better than you think. Even when you screw up, or run into a string of unlucky circumstances. Even if you have an average IQ, went to an average school, and got C’s.
You need not be a superhero or have a super-intellect or do everything flawlessly to succeed. Every day, ordinary people who believe in themselves change the world for the better in some way.
The best thing you can do is believe in yourself. Never sell yourself short.