This is a fundamental truth we teach children in the lunch room as they fight over who gets the chocolate milk. We teach them this because for thousands of years the human species has been plagued with self destructive fights over who gets the chocolate milk.
There is of course the extra credit lesson. If a bigger kid bullies you into giving up the chocolate milk, immediately kick him in the balls and them jam your pointer finger as hard as you can right into his eye and don't stop pushing until your finger nail touches his brain.