Considering I have a dog, it's cool learning that dogs were the first species to be domesticated and has been selectively bred over millennia for various attributes!
I have a Pit Bull named Max who is super sweet.
Dogs are literally man's best friends thinking about it. Their long association with humans has led them to be uniquely attuned to human behaviors.
Yeah they can tell what your emotions are just by being around you
It must be a result of their physical and social evolution. Dogs, more than any other species, have acquired the ability to understand and communicated with us.
Yeah my dog knows a lot of tricks. Do you know how many breed there are?
A quick wiki search seems to show more than 300 species of dogs. 
Wow that is so many! I guess a lot are probably mixes though.