Great to read about the successful outreach event, David!
To formulate your astro talk to non-astro people & especially non-science people is an art form. You need to drop all the astro jargon and use terms lay people can understand and relate to. This takes quite some doing. Worst thing is to bamboozle folks with big words and big numbers that only confuse and intimidate, and they just come away no more sympathetic to astro and only more convinced that it is all just "rocket science". This is a challenge I relish with outreach
Good stuff, mate.
Alex.