I don't think about my passed dogs very much. I miss them, and I cried when they went. But I am usually recovered after a few days or a week or so. I don't know why I'm not as torn up as you all seem to be. Maybe because they were family dogs, and I don't live alone. I imagine if I were by myself and all I had with me were my pets I would become much more attached.
We have five dogs on our property at the moment. All but one are over ten years old. One of our beagles in particular could pass any day now. I often find myself checking to see if she's still breathing. Shes grown overweight as she doesn't move around anymore. Shes got several very large benign growths on her as well. We tried getting them surgically removed three years ago, but they just grew back and she barely survived the surgery and recovery. She had back problems a couple years ago and we all thought we'd have to put her down then, but she recovered. I don't know how I'll feel when she goes, because I've been expecting it for years now. This is her from a year ago, and she looks much older now.