If, after a car accident, you ask 10 eyewitnesses what they saw, you will hear 10 different versions of the same accident, possibly even contradictory ones. None of the 10 eyewitnesses is lying. None is trying to deceive you. Each one is merely recounting the truth in exactly the way they recall it.
Don’t expect that to be different for a speech. We shouldn’t assume that what we say will be recalled by our audiences in exactly the way we mean it. We shouldn’t even assume that what we say will be heard exactly like we say it. Or that what we show will be seen just like we see it. Or that what someone from your audience will say about your speech tomorrow, will correspond to what they are hearing today.
Each one of us has their own reality. We relate new information to this reality. Therefore, we may conclude different things from the same information than others do. Neither of us makes a mistake. It’s just the way that our brains work.
As a speaker, it’s a fact we have to deal with.
