I heard an interview of Peter Scholze [one of the mathematicians of this generation] about learning math, and it seems to me his advice is more related to people that are particularly talented in that area. But what if one is not talented in that area? Should one give up? I think not. You can see this in a few rishonim where Physics and Metaphysics are considered to be part of the learning sessions that one ought to do every day. [Ibn Pakuda, Rambam, and others based on those of the geonim that held this way like Saadia Geon.] This is the whole point of Rav Nahman. What does one do if he or she is not as talented as others? What about us losers? Should we give up? No. There is always hope. אין ייאוש בעולם כלל. "There is no such thing as giving up." That is how I see his method of learning of saying the words and going on. There is always hope.

[I ought to add that there are plenty of rishonim that hold one ought to learn just Torah, but I have not been able to walk in that path. I am not sure why. It is not that I think that is wrong. Rather that it just did not seem to work for me. If maybe I had stuck with it, things might have been different. But after leaving it, I could not get back in. And Rav Nahman said, "If there is one posek [note 1] to depend on, you can depend on him". [That was in response to a question of Rav Natan to him about his fear of deciding a law because of the possibility of making a mistake. ] So I decided to go along with the other rishonim that hold from the importance of Physics and Metaphysics. 

[note 1] posek: a rishon that decided the law. The word "posek" can also loosely be applied to the very early achronim. Not like today where the word is applied to anyone.]