by saying the words one can come to understanding.

There is a way to learn Physics and Mathematics even if one is not talented. See the LeM of Rav Nahman volume I perek 12. על ידי אמצעות הדיבור יכולים לבא  לתבונות התורה לעומקה. "By means of the word, one can come to the understanding of Torah to its very depths." That means that by saying the words one can  come to understanding. Even if very talented people in these subjects do not need that approach, still this method can help everyone get better. 

[Similar to Conversations of Rav Nahman 76. This idea is also mentioned in the Sefer HaMidot of Rav Nahman in the perek on Learning.]

Izhak bn Avraham empasized review along with just saying the words aand going on. That is that one sould review after finishing a whole chapter or book. To listen and learn from an expert from someone who knows the subject well is important as mentioned in the book of Rav Nachman that since we have lost the doing, at least we should hang on to the hearing.