Many people have accented to forgetting things they really read to understanding right in the exams hall.
What is really the need of reading, tarrying day and night and then you can't remember even 50% in the examination hall when it is most needed? Since our system constitutes are different, our abilities are also different. Some read and remember when they are asked in the exams hall, Good!
Some alternatively read but can't recall most of the things when asked in exams. Some instantly conclude that it's a spiritual effect.
They argue that since you do remember things elsewhere and get the reverse in the exams hall, then there is a metaphysical phenomenon there. Are we to believe this? Since we are in an imperfect world anything is possible, and there is enough fact behind the possibility.
Leaving meta-physical effects aside, probably for another day, there could still be physical or natural effects resposible for this. It could CERTAINLY be corrected! Then,
How You Could Remember Everything You Read In The Exam Hall
1. Read well - Always try to read more and more. You cannot remember enough when you have not read enough. If you do not read there is nothing to remember. Get all the required materials and study them carefully before you go to the exam hall.
2. Understand - Understand each line, each paragraph, each page and each chapter before moving to the next one. Every line has hidden details you should take note of.
3. Revise - It is not enough to read a textbook once. Finish it one or two times before the exam day. Constant practice makes you perfect.
4. Solve Questions: - Solve as many questions as possible related to the course. This will help you know what the exam requires from you and the best way to prepare for it.
5. Discuss And Argue With Friends - Discuss the course with your friends around. Organize a group chat or just teach something that needs the knowledge. This will help you remember 90% of what you read. Also, you guys should agree and disagree. Then come to a conclusion.
If you performed all this all to no avail, then you need to try more and more. With time you can overcome the effect. Remember, you can be what you want to be but you may have to face series of problems. Try to rekindle that extra push that is ordinary to be Extraordinary!