When a subject and/or
class, usually in higher education scientific fields, is so convoluted and
hard to follow, that it is impossible for
one to succeed in it. This might be due to the professor, or the subject itself. In this case, the subject acts as a filter, preventing you from moving on to more advanced subjects that built upon it.
This can often extend or apply to specific concepts included or related to a subject or
class.
In any of the above cases, it is fair to say that one has been filtered.
-Did you understand anything from the previous
lecture?
-No, I'm not
even sure the
professor understands what he's teaching.
-Huh. I guess we've both been filtered.