The brain is predicting
Here is an interesting article about how our mind works. The brain is constantly predicting impressions to save energy. It has a number of layers. A higher layer creates a prediction based o a lower layer. The lower layer can report inconsistencies to the layer above, in case we can go a level deeper.
This is probably the same mechanism that intuition uses, as long as we observe something that is in lie with our prediction, we maintain low energy mode, if things start moving apart, we add brain power.
Remember that this is how an audience will be looking at you when presenting.