My absolute MOST FAVORITE Quote that I've ever read is:
"Yesterday is History,
Tomorrow is a Mystery,
and Today is a Gift,
That's why it's called the Present"
To Me it has such a Poignant meaning. I take it to mean that You need to live Your life to the fullest, don't put off til' tomorrow, what You can do today, bcuz Tomorrow may never come. But, also at the same time, don't live in the Past, it's gone and their isnt anything that You can do to change it. It's really a great motto to live by.