I though about this a bit 6 years ago. In the space of 2 months I lost a childhood cat, dog and my favorite sheep. It was pretty depressing. But I had Missy, in her prime, exuding joy for life. It made me smile, it made me happy to get out and do things.
The past few weeks I've had Kipp and Kenzi. At 6 and 2 they are very much full of life and ready to go. It's good to have a dog to get out and do things with. To hook Kenzi up to the bike and watch her lean forward in excitement to GO! To make me smile and laugh. They certainly can't replace Missy, but they are themselves, full of life, looking at me with eagerness and excitement begging to get out and do something. And it's good to get out with them.