Domino Theory of the Mind
Don't let the next topple!
Ever had the experience of failing a long stream of exam or an entire Final Examination? Did you blame it on your luck because you already studied very hard for it? After the first paper which you found particularly difficult, you start to realize you didn't really study hard enough and then you can't do the rest of the papers that came up? The truth turned out to be that the first paper was indeed hard but the rest of the papers were easy and you could have done well if you knew just how to discipline your mind.
The mind is a pattern-recognition system and it has a huge catchment area, meaning that slight semblance of a pattern can activate your mind to conceive it. This is why when you experience something traumatizing that affects all your senses, the fear stays around for very long time and it is very hard to forget the trauma - every little sign or stimulus that resemble anything you experienced during that event would cause your mind to conceive/imagine and thus relive the entire experience. Overcoming this takes a lot of mental courage and discipline.
The same is true for whatever that goes in the mind that cause the 'Domino Effect' for exams. The first paper during the examination period becomes the traumatizing experience and in subsequent papers, you relive the experience, at times even amplifying the fears in your mind. When you encounter a difficult question at the start of the next paper, you start panicking, and after wasting some time calming yourself down you spend too much time trying to prove yourself by attempting the question. This is just one of the ways this effect manifest and cause you to perform poorly for one paper after another. Losing focus, forgetting facts, mis-reading questions, dwelling too long over a particular question you found tricky are all means your experience with the first paper was taking a toil on you.
To avoid getting affected by the 'Domino Effect', we need to isolate the initial domino from the rest. That way when it falls, it does not trigger the other dominos. We should thus clear our minds after each exam to 'reset' our emotion state. This also mean seeing every paper as separate and treating exam-taking objective. You have studied for every subject separately and you've worked hard, there's no reason why you should allow one paper to affect your performance in any others. In your mind, isolate every test-taking or exam-taking experience so that you can treat them fairly and not shortchange yourself.