what is pain’s concept?

Why is pain, pain?
Why does it hurt so much? Why does it feel like your body is in a storm?
It makes your eyes rain,
Rain with dispassion
Always in disguise.
Pain is never truthful, its always telling lies.
So why reall does it exist?
What is pain’s true concept?
All I really know is that’s its hard to resist, or escape
Or debate its only purposes
When will we ever know what pain’s purpose is?