HBS Essay Question

[future_mba]

First of all I wanted to thank you all for providing such awesome resources for us while preparing our applications. Now my question, I am working on my application for Harvard and one of the essay questions is, "What have you learned from a mistake?" As I've reflected on this question over the last few months I really haven't been able to think of any big lessons that I've learned from mistakes. I'm a college senior this year and have been working full-time for the last two years. So far the only idea I've come up with is to write about my intramural volleyball team showing up to our first several games with attitudes of overconfidence and selfishness and learning the importance of teamwork. Is this a good example of something I could use in my essay? The example just seems quite trivial to me, though I can't think of anything else to use. Help please!