You know what you know, but they don't.
I am a slow adopter. I take in new information at a snail's pace, and I am reticent to jump on bandwagons.
So when I finally do own a small body of subject matter, I assume everyone must already know it too.
When I am presenting, I sometimes let this get in the way.
"I won't talk about XYZ because obviously everyone knows about XYZ already."
But it is simply not true.
When we are teaching any audience, we have to remember, if we are experts, we are coming from a place of immersion in the topic we teach and often, if not most of the time, we are sharing foundational truths that are new to an audience.
If you are a speaker/presenter, I challenge you to check yourself on this.
You may have said XYZ a thousand times and think all of your followers/audiences have already heard the goods you deliver, but know that you know what you know, but often they don't.
You might just change a life by including XYZ in your next podcast/live/speech.
They need to know what you know.