I've had a dog make non-trivial progress teaching me to fetch.

I was throwing a ball and it was bringing it back. Each time, it brought it a little further from me. I had to lean out of the couch I was sitting in after a little bit. I still don't know how far it would have gotten if the dog didn't blatantly move the ball back further when I reached for it some of the time.

It's also possible that the dog was trying to figure out exactly how close it had to bring the ball.