I have to say that I got Simon as a puppy and he is almost 2 now (in September) and has yet to "calm" down! He is a lunatic sometimes but I have learned to love that and when he is calm I know something is wrong. I rescued Hallie last July and she is 3 now. She is very calm and much more of a cuddlebug. Simon has a ton of energy and is always on the move.......Hallie is very relaxed, I say she is a diva who needs to be waited on hand and foot so she doesn't have to move