My son Will has wisdom beyond his years. He works very had at tennis, he practices 15 hours a week, participates in tournaments and loves watching it on television. He has a passion for it. At his age you see a lot of players who become very emotional on court, they get angry with themselves when their arms and legs don't do exactly what they picture in their minds. Rackets are thrown, they yell at themselves. Often a match is won or lost on whether they can keep their mind right.
Will almost always manages to keep his cool. He attributes it to a quote he read in Norman Vincent Peale's The Power of Positive Thinking "a peaceful mind is power". While he hasn't read the whole book (he is 13!) he often picks it up and just reads a little bit for a shot of mental energy.
My Amazon Carrousel to the right has that book in it, it makes a great holiday gift for anyone no matter how old or young. Other sources for positive thoughts I like on the web.
http://www.revrun.com/ Rev Run delivers great daily words of wisdom, my kids like his esp!
http://www.dailygood.org/ great inspirational quotes and stories that illustrate them.
Enter my book giveaway (more info here) by commenting with your own fave quote, or posting this link in facebook or twitter and coming back here to comment and let me know. No limit to the number of entries. Have a great week, Jamie.