על ידי אמצעות הדיבור יכולים לבא לתבונות התורה לעומקה This is is an amazing insight from Rav Nahman that just by saying the words one can come to understanding of the Torah in its depths. [Le.M.vol I:11]
If you combine this with Le.M vol I 61 על ידי אמונת חכמים יכולים להוציא משפטינו לאור [by means of faith in the wise, our judgment can come into the light.] then you get this: Start with the fact that the Rambam was wise. And that he included Physics and Metaphysics in the category of learning Torah [in laws of learning Torah], then just by saying the words of your Mathematics and Physics textbooks, you come to understand them. [This does not diminish the importance of review as Rav Nahman himself brings in sefer HaMidot. Rather it leaves the question of how much review and how much of "girsa" {just saying the words} as an open issue.]
So why do people not do this? Because they do not have faith in themselves. See the LeM of Rav Nahman 86 where he talks about that when people have little faith, they need hard services. I.e., just like when there is a time when government is is trying to destroy faith that one needs even to give up his or her life on the slightest infraction, So when there is little faith one needs hard services.
Rav Nathan [a disciple of Rav Nahman] asked him "then what about me who I think I has faith?" Rav Nahman brought the Chazal [statement of the sages] מיעוט אמונה בעצמן גורמת בזבוז שחלונם של צדיקים What causes the destruction of the table of saints in the next world? The lack of faith they have in themselves.
[In our context that means one does not need hard methods to become a rocket scientist. But why people do not do this is because they think they do not understand--when in fact they really do. Just that the understanding is hidden inside and absorbed until much later it is fruitful.]
Of course we all know that "Girsa" is brought in the Gemara itself and is widely known in all he great Litvak Yeshivot. It is more or less practiced as such in the afternoon session from 4PM to 8PM. Yet Rav Nahman adds an emphasis and the further insight that just by saying the words, the ideas are absorbed
See the verse in Proverbs chapter 8 verse 11 concerning Wisdom"כל חפצים לא ישוו בה"".And the Jerusalem Gemara explain this thus: Even the desirable things of Heaven are not equal to it. And the Gra {Eliyahu from Villna] shows that everyone word of Torah (an wisdom) are more than equal to even all of the other commandments combined together.
