Opinions expressed by Entrepreneur contributors are their own. Bold, assertive self-confidence can be conceptualized as an unshakable faith in one’s abilities, skills and competence. It’s a firm ...

This week, depending on when you read this, Faith Kipyegon will attempt to be the first woman to run a mile in under 4 minutes. If you're unfamiliar, she's a triple Olympic champion in the 1500m, a ...