ON ACTING: A Brief Definition

How do you explain the process and craft of acting briefly to a group of non-actors? I found myself in that situation a week ago. The group was not discussing acting, or theater, or film. The topic of the moment was totally unrelated. But when someone in the the group mentioned to another member of the group that I was an acting coach and longtime actor--probably in support or explanation of my previous views on the group topic--I found myself parenthetically explaining to the group that acting was not, as many people believe, "lying," or "pretending," but actually the opposite: "acting was living truthfully within fictitious circumstances." I did not wait for a response from the group, whether they understood me or not, believed me or not, but in short order moved my ensuing remarks back to the topic at hand. I don't know if my definition on acting was understandable to them, or whether they agreed with me or not, or were confused, or. moreover, whether my being an acting coach that viewed his craft in such a manner refuted or supported my general views on the unrelated subject matter at hand. But I do know that I now--as I did then--feel pleasantly content with my brief definition/explanation of acting as "living truthfully within fictitious circumstances." Case closed.