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 are rich or poor, educated of illiterate, clever or dull. Give him your heart and he will give you his. It was really quite simple, and yet we humans, so much wiser and more sophisticated, have always had trouble figuring out what really counts and what does not.

Mostly, he taught me about friendship and selflessness and, above all else, unwavering loyalty.

In a dog's life, some plaster would fall, some cushions would open, some rugs would shred. Like any relationship, this one had its costs. They were costs we came to accept and balance against the joy and amusement and protection and companionship he gave us.

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.

Only then did I see. Something was amiss with Patrick's snap-on one piece, or "onesie" as we manly dads like to call it. His chubby thighs, I now realized, were squeezed into the armholes, which were so tight they must have been cutting off his circulation. The collared neck hung between his legs like an udder. Up top, Patrick's head stuck out through the unsnapped crotch, and his arms were lost somewhere in the billowing pant legs. It was quite a look.

Then I dropped my forehead against his and sat there for a long time, as if I could telegraph a message through our two skulls, from my brain to his. I wanted to make him understand some things. You know all that stuff we’ve always said about you?” I whispered. “What a total pain you are? Don’t believe it. Don’t believe it for a minute, Marley.” He needed to know that, and something more, too. There was something I had never told him, that no one ever had. I wanted him to hear it before he went. Marley,” I said. “You are a great dog.