I have had dogs all my life.  I have learned that they have personalities just like people.  No two dogs are the same.  They have expressions and feel emotion.  The funniest thing I have found is that dogs get embarrassed and can blush.  They lower their heads and give you the side ways look as if to say "You didn't see that did you?"

Cats on the other hand are very different from dogs.  They don't wear their emotions on their sleeves.  They are too cool.  They want to be where you are, but not acknowledged.  "Look at me, but pet me only when I say you can."  Like dogs, cats have different personalities also.  Some are more outgoing than others, most are happy sitting in the window watching the outside world.

All in all, pets are like your children.  They need love and attention, but freedom to be themselves.