Rhetoric is magic. But just like magic, it has its dark side. Just as J. K. Rowling gave her magical world the three 'Unforgivable Curses' -- Imperio, and Crucio, and Avada Kedavra, so rhetoric has it's own. It has Skotison, and Pysma, and Procatalepsis -- word structures designed to befuddle or destroy.
Giving a TEDx talk? Fantastic! You must be thrilled/terrified/nauseous/overwhelmed! Certainly, there's a lot on your mind right now--your talk has a lot to live up to, and you're probably feeling the pressure. How are you going to get your message across? Is it going to be interesting? Where to start?