"I taught my dog to whistle"
"I can't hear him whistling"
"I said I taught him. I didn't say he learned it"
(from David Minton)
Just because you've done a presentation doesn't mean you have changed the audience. Did you think about what the audience wanted and why would they bother learning to whistle? Too many people present without thinking it through from the audience's point of view. How does it affect their lives? Why should they bother to learn this new skill? What part of the presentation grabbed them? A presentation is not just about delivering it, it’s not just about getting it over and done with, it’s about understanding the audience thinking process. So think audience, audience audience or you'll end up barking up the wrong tree.