Time’s serial. It just passes by.
When we read a book, we are in control of the pace with wich we process the information. We can slow down to read less in a given amount of time. We can also skip ahead or turn a few pages back to re-read some information that we need to refresh.
When listening to a speech we can‘t do any of that. We are not in the driver’s seat. The speaker is. If she’s driving too fast, we’ll miss the point. If she’s choosing a bumpy road, we‘re probably not going to enjoy the ride. If she’s driving too slow, we’re likely going to fall asleep.
As a speaker, being aware of that helps a lot in making the ride more enjoyable and satisfying for our audience. Keep in mind, though, that not everyone enjoys the same kind of ride. While some love the feeling of a sports car others prefer the feeling of a well-balanced limousine.