Secrets for Success & Happiness

I just started reading Og Mandino's book, Secrets for Success & Happiness, I'm really enjoying it so far. There's a great quote in it from Henry David Thoreau, and here it is.

Pursue, keep up with, circle round and round your life, as a dog does his master's chaise. Do what you love. Know your own bone, gnaw at it, bury it, unearth it, and gnaw it still.
However mean your life is, meet it and live it; do not shun it and call it hard names. It is not so bad, as you are. It looks poorest when you are richest. The fault-finder will find faults even in paradise. Love your life, poor as it is. Humility, like darkness, reveals the heavenly lights. Superfluous wealth can only buy superfluities. Money is not required to buy any necessary of the soul.
-Henry David Thoreau