Over the years, my wife and I have been blessed with 15 cats, three rescued from the streets of Brooklyn, three from barns near our home in Vermont, one from a Canadian resort and the others from the nearby shelter, where my wife has volunteered as a “cat whisperer” for the most emotionally scarred of its feline inhabitants for years. Twelve of our beloved pets have died (usually in our arms), and we could lose any of our current three cats — whose combined age is roughly 52 — any day now. So, I am either the best person to offer an opinion on Caleb Carr’s memoir, “My Beloved Monster,” or the worst.