I usually tell people that planes fly by pushing air down and backward: down so the airplane doesn't fall and backward so the airplane moves forward. I tell them this because otherwise they completely forget, and jump into assertions about implementation details like laminar airflow.

Now I know to _first_ talk about air going backward and down and _then_ to point them at the conclusions section of this article, referring them to the body of the article for detail. A-and then I'll get back to my work so I can get home at a decent hour.