Have you ever wondered why we choose the dogs we do to share our lives?As a longtime lover of dogs, I’ve often wondered why I’ve chosen certain dogs over others through the years.As I reflect on all this, to my delight, if not my editor’s, dogs long gone and some still living, echo through the canyons of my memory. Most were large, a few were small. Most were mutts, a few were pure bred, with papers to prove it.The canine characteristic most common to the dogs I’ve known, owned and loved unconditionally since boyhood is friendliness.