Do you have a dog? I have a MaltiPoo named Bella, she is the cutest thing ever!
I have two shepherd mixes.  Dogs were the first species to be domesticated
That does not shock me, they are great companions. I used to have a German Shepherd, great dogs, but a bit too big for how aggressive they could get
I haven't had any issues with aggression, but it's not surprising seeing as their closest living relative is the gray wolf
That is why we got a smaller dog, because when they are excited to see you, they could knock you over, but my dog cannot 
They're always excited to see us!  They can be uniquely in sync with our behavior because of their long association with humans