In order to memorize what you have read, It is a good idea to write notes. The notes can be written in the margin of a book while you are working or in a separate document. A writing session can consist of writing down everything you know about a topic as a stream of consciousness. Structure, organisation and correct spelling is unimportant when doing so. The purpose of the exercise is to get a quick overview of what you know.
After you have written down everything, you get simultaneously an overview of what you know and what you don’t know. You need to practice more on the part of the curriculum that is not included in your text.