I know what you mean. We had 2 lovely border collies and when we lost them to old age I decided we would have a different breed. Ended up with a Leonberger who is nearly 8 months and over 40kg already and a Clumber spaniel who is 5 months. They are nothing like the collies and nothing like each other. After a training session I feel as if I have done hard day's work. I'm not sure if they are keeping me fit or finishing me off - I was 73 yesterday which accounts for the last comment.My first dog, Andy.
Edited to add: Every dog since pales in comparison. To the point where I don't know if I can ever have another golden.