Many of the qualities that come so effortlessly to dogs - loyalty, devotion, selflessness, unflagging optimism, unqualified love - can be elusive to humans.

A dog doesn't care if you're rich or poor, educated or illiterate, clever or dull. Give him your heart and he will give you his.

Never slow down, never look back, live each day with adolescent verve and spunk and curiosity and playfulness. If you think you’re still a young pup, then maybe you are, no matter what the calendar says.

Dogs are a really amazing eye opener for us humans because their lives are compressed into such a short period, so we can see them go from puppyhood to adolescence to strong adulthood and then into their sunset years in 10 to 12 years. It really drives home the point of how finite all our lives are.

Such short little lives our pets have to spend with us, and they spend most of it waiting for us to come home each day.

A dog is the greatest gift a parent can give a child. OK, a good education, then a dog.

A person can learn a lot from a dog, even a loopy one like ours. Marley taught me about living each day with unbridled exuberance and joy, about seizing the moment and following your heart. He taught me to appreciate the simple things-a walk in the woods, a fresh snowfall, a nap in a shaft of winter sunlight. And as he grew old and achy, he taught me about optimism in the face of adversity. Mostly, he taught me about friendship and selflessness and, above all else, unwavering loyalty.