Even though she has lived with me for a couple of years now, in many ways Scout is still a mystery to me. She came to live with me at 4 months old, so I missed out on those formative early weeks. She lived in a house full of other cardis, both older dogs and other puppies.
On the other hand, I got Spencer when he was exactly 8 weeks old. After a few days, I wished that he had stayed with his momma and siblings a little while longer, so they could have had the job of teaching him bite inhibition, and would have saved my toes and fingers from his sharp little teeth. But we got through it, and by 10 weeks old, he was going everywhere with me, meeting lots of new people, and playing with other dogs at puppy class.
Spencer has always been a playdog - either with other dogs, kids, people, or just by himself, playing with toys. He would toss them around, stalk them and "catch" them and give them a good shake. When I picked him up at his breeder, I took a little sock monkey for him. We rubbed the sock monkey all over his mom, and for several weeks, he carried his sock monkey around the house, and would play with it often. One day he discovered how to dissect (and de-stuff) the sock monkey, but even after I threw the stuffing away, he still played with the monkey "skin."
Since then, he always promptly de-stuffs his toys, but continues to play with the skins. He loves to play tug with them. He will jump around in front of me with one in his mouth until I grab it and tug with him. He tries this with Scout, but she just doesn't get it.
So this brings me back to the mystery of Scout. She does not do toys. She does not understand when Spencer tries to lure her into a game of tug. I've tried to find a toy that would get her excited so that I would have something to reward her with in training - nothing gets her excited. I think she could be a great flyball height dog, except that I can't get her excited about getting the ball.