... is that once you start using a nose hair trimmer (that your ex got you for xmass as a cruel joke the year you split up), you can never stop or you will look like a neanderthal. Your nose hairs will be known and seen from far and wide, as they wrap the outside of your nostrils and proceed to reach and cover your eyes and lips. Small children may go missing, only to be found as adults tangled up in hair, hanging from your nose.
I think I remember a similar realization after I began plucking my eyebrows. Someone told me I should pluck them, I listened, and now I am subjected to a life of tweezers, wax, or cave woman style.