Nancy Duarte helps people make better presentations. She's worked with all the big names: Google, Apple, and dozens of TED speakers.
"A hero ventures forth from the world of common day into a region of supernatural wonder: fabulous forces are there encountered and a decisive victory is won: the hero comes back from this mysterious adventure with the power to bestow boons on his fellow man."
It did make sense that the speech would be a hero's journey -- speeches are about the story, and vision, and overcoming obstacles, and adventure. But something about that model didn't seem right. Then, she realized in a flash the mistake she had made.
A speech -- the sharing of ideas -- is indeed a hero's journey. But the hero in the journey is not the speaker. The hero is the audience.