Wired recently challenged neuroscientist Bobby Kasthuri to explain what a connectome is to people with five different levels of potential understanding: a 5-year-old, a 13-year-old, a college student, a neuroscience grad student, and an expert neuroscientist. His goal: "every person here can leave with understanding it at some level".
Watching this, I kept thinking of Richard Feynman, who was particularly adept at describing concepts to non-experts without sacrificing truth or even nuance. See him explain fire, rubber bands, how trains go around curves, and magnets.