When two third graders see some nice shiny stones on the school playground, it makes sense that they want to keep them or collect them.
If the stones are not totally clean, it makes sense that they would want to clean them.
It makes sense that stones are like teeth, with a similar consistency and hardness.
It makes sense that if one wants those stones to be clean, one should use a toothbrush with toothpaste.
It makes sense to bring one’s toothpaste and toothbrush from home to school to do the cleaning job, during recess.
It makes sense that clandestinely trying to squeeze toothpaste out of a tube would get one’s pants and shirt and face minty and sticky.
It makes sense that you would apply a generous amount of purell to clean the toothpaste off of the stones; after all it’s just like rinsing your teeth after brushing them.
It all makes so much sense, that I am shocked that I didn’t anticipate the whole thing before the school year even started.