I think we humans can over analyze things.
I think emotional pain and physical pain aren't so different from each other and both serve the same purpose - to protect the individual from anything that threatens its survival. At the heart of it pain is simply an uncomfortable perception that urges the organism away from its source.
Its all about survival, man.

Why do we overthink it? Because our ancestors began to eat animal protein and our brains became increasingly complex.
Now we are doomed to ruminate upon the paradox of our own existence for all eternity...

I am, therefore I think.