Humans
There is nothing in the world so irresistibly contagious as laughter and good humor.
Charles Dickens
Talking to a seven year old human boy:
Boy: When I was two, my parents bribed me with toys to put eye drops in my eyes.
Me: You remember that when you were only two?
Boy: Well, I was 2 turning 3.
Humans are pretty cool species. More to come because humans are awesome.