Time...

Time... just a word, or is it not? Time is the most valuable thing you have in your hands, you can't buy it or sell it, give it or take it... It's yours and yours alone until the day you die. And the worst thing about time is that it's running out fast... Faster than you can possibly imagine. So be careful not to waste it! Savor every moment, every second, before the future becomes present and the present becomes past...

http://www.youtube.com/watch?v=LqRZ2_w56U0