A mowed yard, a tennis ball, and a human to throw it over and over and over again.
Or, in Caleb's case, to sit and watch Simon do that over and over and over again and make fun of him.
It's interesting. All of a sudden Caleb's just shot up, shot out, and is looking less like a puppy and more and more like a mini-adult. I swear he's grown five inches and four pounds in the last week, and he's ravenously eating anything in sight.