In ancient times, awe and terror would often overwhelm a person without his knowing what it was that affected him so.
And he would have to do something to escape from the situation.
So too, with someone studying Torah – his soul reacts even if his outer consciousness does not.
Perhaps, this simply makes it possible for a person to be engaged in Torah.
For if one were aware of its awesome power, it would hardly be possible to focus one's attention.
Man's dull-wittedness is often his protection, enabling him to relate to sacred texts without being consumed by them.
There is a tale which may illustrate this.
A great king ordered the manufacture of a special crown, providing for this purpose extremely valuable jewels and ornaments.
The master jeweler prepared the frame, but when it came to setting the priceless jewels in their place, he found his hands trembling with anxiety lest something go wrong.
He called a local rustic, who had no idea of the value of the jewels, to put them in place, and the task was done simply, without any excitement.
In this way too, an ordinary person who does not appreciate the terrible holiness of what he is doing may read Torah and even determine Halachic procedure and ritual.
There seems to be an odd paradox here.
The physical being of man, notwithstanding all its innate evil impulses and limited comprehension, is what makes it possible for him to engage in Torah.
In certain respects, it may be likened to the special protective mask that welders wear to avoid being blinded by the intense flame.
–Rabbi Adin Steinsaltz
From "Torah as God's Will" in The Long Shorter Way by Rabbi Adin Steinsaltz