In what way would the mind be classified an "illusion"?

Someone responded to my question with a statement saying that the mind is a “philosophical illusion”. I was curious to know what others would perceive this response as denoting. Is the mind truly an illusion simply because we are creatures who were nurtured to learn and follow norms? Or is the mind not an illusion and we innately perceive things because we are naturally skilled to create (language, ideas, pictographs, etc…)