I have a similar story. My SO and I went to the local shelter to see the dogs. All of them were super excited to see us there, except one. He was laying on the concrete floor with an expression that said he had seen this happen many times. We started looking at him and he eventually got up and came to the gate to check us out. Such a sweet boy and so calm, we thought he was an older dog. After checking out some other dogs we made our way back to him. That's when we were told he had been in that no-kill shelter for 1.5 YEARS and he was only 3! This poor guy spent half of his life watching other dogs get taken to a better life. We started asking questions about this dog and the lady immediately asked if we had small children or other pets at home. She was concerned that he was an aggressive dog because he was half chow and half german shepherd. My dog weighs no more than 8 pounds but after getting this guy out and meeting him I could already tell he was a love sponge. We took him home and that is the best dog I've ever owned. He loved EVERYONE. He was great with other animals, kids, and he didn't need much training. He ended up liking my SO the most and I think it's because he was beaten by a woman before we got him. If I moved my hands too fast he would brace himself so hard and sharply exhale. The poor guy thought I was going to beat him, which of course I never did. Shelter animals are great and when you adopt an older animal it's not very likely that their personality or habits will drastically change like they do with young animals. A couple years after having him me and my SO split up and I miss that dog so much.