SPOILERS FOR I AM LEGEND TO FOLLOW.
In I Am Legend, Robert Neville has a dog named Sam. Part way through the film we learn that Sam is short for Samantha. It completely changes how we perceive the dog at that moment. I, for one, cried harder at her death, and I'm not the only one.
Why? Why does it make such a difference that the dog is a girl?
[edited to add: This is more of a philosophical question than one looking for a finite answer.]
