Often most parents complains that their ward cleared many hard subjects but could not cleared the easy subject. The students perception about the subject makes it easier or harder not the course content. In many instances its cumulative effect of teacher'teaching methodology, students preconceived notions on teacher, and ofcourse the opinions of surrounded friends. For instance if a better performing student says an easier subject as tough its effect will be felt more or less till to the relatively low performer. Its ripple will be felt all over.
Best way to be out of such scary situation is getting familiarised with jargaon of subject. Students must carry the mood anyway i need to sit an hour in the class then why not in spending the same time in listening atlest minimal technical words. Above all always carrying good opinion about teacher will boost the understanding by 10-15%.
Good luck friends. Happy reading.