Marques Colston is a former NFL wide receiver with the New Orleans Saints whose team took home a Super Bowl trophy in 2010. He's also an investor and entrepreneur who has turned his experiences into an executive education course at Columbia Business School. While aimed at professional athletes, the advice he gives could help all leaders trying to make their mark.

Irrational confidence, says Colston, fueled any success he's had on or off the field. It's a mindset he teaches students in his course that blends risk-taking with old-fashioned consistency and hard work. This approach is one he says can help anyone focus despite nearly impossible odds.