You don't really need compsci to understand that. A pure function is more of a declaration of truth than a list of steps. When your whole application is made u

You don't really need compsci to understand that. A pure function is more of a declaration of truth than a list of steps. When your whole application is made up of declarations of truth, it is simpler to reason about and rearrange. It's simply the fact that the function depends on nothing but its inputs (but includes all the surprising ramifications of that).