In mathematics we have complex numbers and concepts, like the square root of minus, one that can never be used for ordinary purposes of life or imagination.
They are beyond description, beyond the grasp of mind, even though they can be considered real in terms of mathematical manipulation.
With such abstract concepts, the mind is not wholly integrated.
Not only do they fail to create any experience, there remains something fragmentary about them.
There's an edge beyond which one cannot go.
The abstractions of the Kabbalah, however, are of a far more intimate character.
They come from Divine Wisdom and speak to the individual soul where life and reality and imagination have their own way of integrating ideas.
As an aside, we could point to the fact that many highly intelligent and creative people have trouble with abstractions as such.
One eminent physicist, fully aware of the enormously complicated mathematical steps leading to the identification of certain particles, admitted that he needed to visualize them as pink and round (with color and quality) in order to pursue his studies.
One is able to perform with only a minimum of understanding, but to create meaningful contact, some kind of deeper understanding is usually necessary.
When one studies the revealed Torah, therefore, the grasp can be complete; in studying the esoteric Torah, the grasp is necessarily partial.
–Rabbi Adin Steinsaltz
From The Candle of God, p. 97, by Rabbi Adin Steinsaltz