The idea is the following. There is a bullet which hurtles down at breakneck speed towards a wall (say). As a cruel joke, the bullet's been provided with butterfly wings. So as not to smash head on to the wall, the bullet tries its best to flap its teeny-weeny pellucid little worthless excuse of a wing to save itself from inevitable destruction. Unfortunately for the bullet, the laws of physics, the eternal party poopers, guide it towards its imminent doom.
With or without the wings - butterfly or otherwise.
And then comes the chorus:
Despite all my rage I am still just a rat in a cage
Heh, I love big, fat, rich rock bands making infinite money off their own suffering, getting richer and doing it all over again.