I realized that enough people didn't understand: (in no particular order)
-- the difference between freeware/shareware and Free software
-- the ambiguity of the English word free
-- that FOSS is based on copyright
-- how copyright works, copyright assignments
-- differences between copyright, trademarks, and patents
-- source code vs. binaries
-- the phrases "public domain", "Shared Source", "copyleft"
-- why "source available" isn't freedom
-- how the GPL actually works
-- what "Linux" is (kernel vs. distros)
-- why people use open source: all intersections of freedom, cost, control, eyeballs
-- dual licensing (open/open, open/proprietary)
-- the Open Source Definition, and how many compliant licenses there are (but basically BSD/X-ish vs. GPL)
-- background on oft-heard zealtory/advocacy talking points
I started sketching it all out on a pad of paper and I think I have a general sort of plan to lay it all out without dependency loops. And if I can find all the images that I think I can, it should be visually entertaining too.
The fact that half the audience is non-technical is the best part: I can avoid going into too many details (e.g differences between each license) which would bore both halves.