You have only one life. And as Benjamin said, life is made of time. Every hour wasted is a piece of life wasted.
You only have NOW.
Don't wait for a perfect moment, or "when I have time", retirement, vacation, tomorrow.
It has been said "life is too short to read bad books". Life is too short to do things you don't really want to do, things that lead you to nowhere on your road to your dreams, spend it with stupid people, waste it on things that don't really need to be done.
Your life is not a waiting room!
Your life is not a rehearsal!
Your life IS a novel.
Make it good. Make it interesting. Make it worth reading!