IF A TEACHER CAN'T TEACH ALL SUBJECTS

Let me rephrase the question:

If a teacher can't teach all subjects, then how could we expect a student to learn all subjects?

This is the answer:

Teacher's knowledge about a particular subject = Approximately 80% - 99% of the whole knowledge.

When the teacher teaches the students, then the teacher teaches them according to the syllabus. So, the students only learn around 1% of the knowledge.

Let say there are 10 subjects need to be covered by the teacher and learned by the students.

When the teacher needs to teach all subjects = 80% X 10 = 800%
However, when the students learn all subjects = 1% X 10 = 10%

Now, back to the question above.

If a teacher can't teach all the subjects (means a teacher cannot provide 800% of the knowledge, at least 80% can be provided) but we can expect a student to learn all subjects because they learn only for 10% from the whole knowledge!

Just remember this, dear students - YOU WILL NEVER LEARN THE WHOLE SUBJECT in school.

Am I answering your question? Hopefully, yes.