Have you ever had a big game, or some other moment which has marked the rest of your life in some way? Everybody who has done a sport for any significant length of time has had such a substantial, memorable occasion which they can still bring up. You can often tell the people who are successful from the people who are not because of the most memorable occasions they can bring to mind from their athletic days. The more successful a person is, the better their sports related memory tends to be.
Of course, not everyone can bring up a memory like that so quickly. For many people, their athletic days are only just beginning. If you are in a position where you have the opportunity (and perhaps even the responsibility) to mentor young people, you would be wise to encourage them to work their hardest to remember the good parts of their athletic endeavors. While the more successful people will naturally do this as a matter of how they run their lives, the less successful people are going to mostly visualize their most epic failures.
There is a definite relationship between the images that a person sees in their mind and the reality which they construct with their actions. While that might sound kind of new age, this has been proven in laboratories for decades. What a person thinks about impacts how they operate in every part of their lives, and the people who mostly just remember their failures are the types of people who tend to repeat them. Just encourage your students to focus on remembering their past successes, and they will almost certainly end up repeating those successes in their later lives.