"Tuesday has a personality that shines. I am not kidding when I say it is common for people to pull out their cell phones and take pictures of and with him. Tuesday is that kind of dog. And then, in passing, they notice me, the big man with the tight haircut. There is nothing about me--even the straight, stiff way I carry myself--that signals disabled. Until people notice the cane in my left hand, that is, and the way I lean on it every few steps....