They ask you to give a presentation to your customers, peers or superiors because you have the knowledge in the subject; you do it every day, you master it and you are known to be the one …
the expert in the attic!
You give your presentation and you realize that you are not reaching your audience. You are hiding behind your expertise and none of it means anything. You are giving a long one-sided conversation.
You are just giving a monologue.
Great presentations don't come out of nowhere. It requires preparation, refinement, revision, practice … and the skill to interact with the people you seek to change.