Very few people follow every part of a course with equal interest or understanding.

Even experts on a subject will tell you, it's impossible to know everything about it.

Most courses have a pass mark of forty percent. This means you can pass with far less than a complete knowledge of the subject.

Most exams give you a number of options, so you can answer on those topics which you know best.

Don't let some minor gap in your knowledge give you cause for anxiety.