I can see the difference between Oden and Zeus, of course it is kinda of an unfair comparison. Poodles were found to be one of the smartest of breeds second only to Bordercollies (but who needs all that shedding), and Zeus is a Greyhound and well............he's really sweet

. Oden house broke right away, he learns a new trick on the second or third try, and does not forget where you've hid a toy to keep it away from him.
Zeus was kept in a crate, on a Greyhound farm for the first 2 years of his life, and did not even understand affection when we first got him,
everything in the "human" world was new to him. I am suprised how quickly he has bonded to me, and the attempts he makes to do the tricks. But he does not learn as quickly. How much of this is breed difference and how much is the training or lack of training they each recieved as puppys I could not guess.