Adversity.

The quote means that adversity can either make or break you. Sometimes people don't know how to handle all the pressure they are in, and just give up. Then there are people who work well during times of adversity and succeed.
The U.S. is going through a time of adversity right now; having to do with the economy. Most pro athletes have most likely dealt with adversity, but that's what makes a "pro"; going through tough times and still be able to be successful.
Personally speaking, Its hard to deal with adversity, especially concerning school, but I just remember that I'm not the only one that feels that way. Adversity I might face in the future most likely would have to do with school. I just have to keep believing in myself and in God.