Learning is a graph. Remembering many modes will create the higher abstraction of learning the shape and the sometimes abstract properties of the graph. If you

Learning is a graph. Remembering many modes will create the higher abstraction of learning the shape and the sometimes abstract properties of the graph. If you read a book you might not remember the previous pages, but if you start in the middle you wont understand anything. The nodes of knowledge might be forgotten, but its ok if you have the graph. The nodes of knowledge that were available to you initially might have been biased. Then you need to unlearn, that is often harder.