The level of G-dliness drawn below through Torah study depends on the persons Bittul:

Although every Jew who studies Torah recites and repeats the same words, assuming they are studying the same subject, nonetheless, the effects of the Torah study of each Jew differs from one to the other, and is dependent on their level of Bittul and nullification that they have to G-d during the study. One cannot compare the amount of G-dliness drawn below as a result of the study of individuals such as Rabbi Yehuda and Rashbi, versus that of a regular individual. The unparalleled level of self nullification and submissiveness that these sages felt towards G-d allowed them to draw down a much greater quality and quantity of G-dliness through their Torah study, versus that of other individuals.

Torah Or p. 68b-69a