On the subject of how playful different dogs are, here is something I noticed.
I have walked Bailey off leash in the woods on the same paths in the same area for two years. He like it, but does not run around and get excited often unless we play fetch, or another dog shows up. But...........for example, today I took him to a place he has never been before. He was very excited and did a lot of running around. That is more typical for Bailey in a new location. And it stays "new" for many visits too. Eventually it gets "old".
I wonder sometimes if a Corgi sees a big dog like a Mastiff or a St. Bernard as something to be herded. Bailey seems to. He instinctively herds the St. Bernard puppy. And he grabs the Mastiffs ear in a dominant, but not very serious gesture. Using a submissive gesture when ever needed.
When Bailey meets another Corgi, after an initial examination, he hardly cares about them. I think there may be something triggering the herding instinct in some dogs he meets and not in others. He does not spend much time with dogs his own size. Usually he likes bigger dogs, the bigger the better. And they like him. When Bailey herds a big running dog, occasionally a border collie tries to herd Bailey and the big dog. This is confusing for them, each herding dog wants to be the only one, and is a little annoyed at another herder. They never fight, but they keep trying to be the one in charge of herding. It's like two kids arguing over a favorite toy.
It's actually pretty funny.
"It's my turn".. "no it's not" .."yes it is"..
Of course this in not the only thing going on, the "chase" instinct is involved, and there is no way to know for sure, but it may be one of many factors involved in a dogs personality "programming".
Since dogs learn by, and like repetition, the past life style has to have some effect. How much is hard to know.