A man and his dog

They always say that man and dog become more like each other over time. I think there is definitely something in it (or maybe man picks the dog right from the outset that is closest to himself)
There is a lovely children's book called "Mr. Miller and his dog" which illustrates the theory quite nicely. It starts off with Mr. Miller sitting in his armchair and the dog being so well trained it fetches his paper for him. Time goes by and at the end so much metamorphosing has taken place that the dog is sitting in the chair with Mr. Miller fetching the paper.