Question

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

Answer 1

Do we have to explain this? If yes then.....
People generally think that the greatest enemy of true enlightenment, a.k.a., knowledge is ignorance or not knowing. But, in reality, the greatest enemy of knowledge is the illusion of knowledge, i.e., being under the false impression that you know something but don't actually.
In simpler words, it means that being in false assumptions that you are knowledgeable is more harmful to gaining true knowledge than not knowing it.