Charley's law is similar to the laws of physics, for example the laws of physics state "what goes up, must come down". in Charley's law is says "no matter what your mum will be irrelevantly brought into a conversation at least once a day."
person 1. "isn't it a spiffing day today?"
person 2. "yes your mum is spiffing!"
person 1. "do you think that as the human race that we are to naive and ignorant in the sense that some of use feel that we are the only intelligent race or that we simply don't care, for all we know we could just be an irrelevant race compared to something else out there?"
person 2. "I LIKE FUCKING YOUR MUM!!! HAHAHA!"