I was preached that line since I was a little boy by my father and my coaches from Little League through college. I believed it then, and I have preached it myself to the kids I coached and to the students that I have taught.
An implication of this, is that you exalt the examples of those who get the most out of the least, while condemn harshly those who get the least out of the most.
At the end of December, The Painted Area: One Tough Hombre of a Basketball Blog, the All Decade NBA Underachiever Team was named. The list includes Stephon Marburgy and Bryon Davis (MVP) and Rasheed Wallace and Lamar Odam (surprising, but there were huge expectations on him since HS). These all make sense. But I think the best choice is Tim Thomas. Thomas is from NJ and had all the physical tools to be great and he had moments of brilliance both at Villanova and in the NBA. But the consistency never could be found. (Hat-tip to Kevin Grier).
Reading this post made me wonder --- there are underachievers and overachievers in every walk of life, not just in sports. And the sin of wasted talent applies equally as well. Clearly there are underachievers and overachievers in the field of economics. I think the story of the overachiever is fascinating and I would point to John List as an example, not because he doesn't have a great natural endowment of talents (he obviously does) but his career didn't follow the normal trajectory of the elite in the profession. Roland Fryer would be another who climbed the professional ranks in an atypical fashion. Both of these extremely talented economists made the most out of the opportunities presented to them. They are good role models to follow.
The underachievers are harder to name (for obvious reasons), but I am sure everyone has some candidate in mind.
Just remember that to whom much is given, much is expected. And you need to work in proportion to your aspirations.
Don't be Tim Thomas, be more like Steve Nash (only 1 D1 scholarship, but made the most of that, now even though small by NBA standards [he is 6'3"], he was named NBA MVP 2 times in the mid-2000s; and in 2009-2010 season he is averaging 18.5 ppg, and 11apg). And, of course, if you can be like Mike (or Magic or Larry) than be like Mike.