I absolutely love this quote. It can be looked at from so many different view points. My life is a constant question of what would I do if I could and what SHOULD I do. Always follow your heart.
Some final inspiration:
"Happiness doesn't depend on any external conditions, it is governed by our mental attitude." - Dale Carnegie
"Happiness depends on ourselves" - Aristotle
"Happiness in intelligent people is the rarest thing I know" - Ernest Hemingway
"The purpose of our lives is to be happy" - Dalai Lama
"You didn't have to run... I knew it was love from a mile away."