There is a vast difference between understanding and knowing. The Parrot is very nice and very entertaining BUT he never says anything new. Like a computer, you put data in and you get data out. Likewise, RINROUT (rubbish in – rubbish out) is still very valid a description.
Speakers that sound authentic are those that don’t read notes and speak from the heart at the moment. This is not to say that a certain amount of preparation is not required. Some people though overthink their message to a point where the only person that could understand it, is them.
When I was a Further Adult Education Tutor I had some wonderful assignments submitted for BTEC portfolios. Awesome, much better than I could ever write myself. My trick was to ask the student to explain to me in his own words exactly what his assignment was about. I had a couple of very clever genuine London Underground Apprentices who easily did that. Most however floundered and admitted they had speed read the materials on the internet and just put it in words that they understood. They understood what they had written on a very superficial level BUT this would not be good enough in the real world of work. You can waffle on all day about gravity, produce drawings and sketches, impress with mathematics or you could just say.
“See this apple? When I drop it the apple always goes in one direction. Down, and that is what gravity is.”