Business Insider reports, former Pizza Hut worker Nichole Mustard is a true success story. After not really knowing what she wanted to do in college, she founded her own startup, Credit Karma, which now employs 800 people and is valued at $4 billion. Credit Karma is "a consumer credit score company." Mustard states the secret to her success is that she focused on her own happiness. It's what helped her keep persevering through tough times.