Answer: The more a person studies, the more he enters a state when he feels and understands nothing. And then he overcomes this barrier.
It is a very interesting experience. It is written that at some point, Rabbi Shimon felt as a mere merchant, "Shimon from the market." That is, he felt as if all knowledge, perceptions, and impressions related to the wisdom of Kabbalah disappeared in him.
However, in correspondence with the darkness that enveloped him, he also felt the spiritual degree he was about to attain. After all, when a person is evolving spiritually, the gap between what he has achieved during the ascent and the place where he “falls” having lost everything is enormous.
Therefore, when you are surrounded by darkness, study it thoroughly and understand how it manifests; only this will help you. Examine what is happening, what feelings it instills in you, what you are desperate for, where you have no more emotional resources, and where you still do have some. This is what you have to clarify at the time of spiritual darkness. It is so-called “work in the night,” a period greatly valued by the sages of Kabbalah, as it is said: “To proclaim Thy mercy in the morning and Thy Truth in the night” (Psalm 92).
In other words, in the darkness, a person starts discerning what is going to be revealed to him since darkness is the reverse side of the Light. And when you don’t just sit and “eat” yourself but study the darkness correctly, the “morning” arrives and the Light illuminates everything. Hence, inside this darkness, a person has to see the Light, examine what it is he has to attain, and while still being in the dark, to feel that he is coming closer to it.
To be in the dark is a very rewarding job! It is a special state. This is how we are shown that we are unable to do anything ourselves. A person finally gets to know his true nature and realizes that without help from Above he is nothing.
If you are illuminated by the upper Light, you rise like a flower stretching up to the sun. And if there is no Light, you immediately fall.
From the Introductory Lecture in North Tel Aviv 12/19/2010