The key to succeeding with every performance with an audience is to strike the right balance between spontaneity and preparation.
If an amateur public speaker steps up to speak with all spontaneity and no preparation, she is likely to stutter and stammer. If she is all preparation and no spontaneity, her speech would sound mechanical and scripted.
The right balance makes the best use of our limited working memory. Our memory is split into short term working memory and long term memory. Working memory works similar to a computer’s RAM. Too little spontaneity and performance is sub-optimal, because working memory is underutilized. Too much spontaneity and working memory is overloaded, causing stuttering and freezing like an overloaded processor.
Great performance is mostly about memory management. Preparation stores information in your abundant long-term memory, while freeing up your working memory for a spontaneity.