It happens sometimes that we read something important but later when we need it, we just can't remember. If we can't remember then there is no point. So to remember everything we just need to do a brain exercise.
Take notes of things you need to remember. Practice the generalizing exercise which will come in handy. After finishing reading, sum up the whole matter. And then write down the important things you need. Later when you need to remember the whole thing, the clues will do their job!
This exercise can be used for everything such as for any book that will not be with you anymore, movies, during school or university. We do that many times in school. Highlighting the main points, remembering the names of the characters, their appearance and actions can help us remember things clearly and easily.
The worries have come to an end. It's time to remember everything without any tension.