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

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

Cats will outsmart dogs every time.

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.

When I wrote 'Marley & Me,' I had a clear audience in mind. And it did not include children. I wrote my book for adults and assumed only adults, and possibly teenagers, would be drawn to it.