Don't believe self-deception. Not only is it a question of social acceptance, but the self-study exam itself can't learn anything valuable. You can learn a little from the exam. Most of the knowledge you have learned is rote learning, even for engineering majors. It's useless for you to learn engineering without remembering simple concepts ... not to mention that cheating in self-study exams is rampant in many places, which leads to diplomas in society.