There are four different types of students. Number one: somebody who is quick to understand, but as quickly as he understands something, he forgets it. He’s not somebody with a memory. He easily forgets what he learned. We say that, for this type of individual, the gain from understanding things quickly is outweighed by the tremendous loss from forgetting them. So the fact that he understands things very quickly sort of becomes irrelevant because he forgets them all. He forgets them, so he has no memory. This person has a difficult situation.
Number two: somebody who is slow to learn, but once he learns something, he’s very slow to forget it. The loss he has from being slow to learn is outweighed by the fact that he doesn’t forget things. So, okay, even though he has to work hard to finally understand an idea in Torah, once he understands it, he doesn’t forget it. Therefore, he has a tremendous ma'ala (advantage), even though he doesn’t learn things quickly.
Number three: somebody who is quick to learn, understands things, and is also slow to forget. That type of person becomes a wise individual through the combination of the two. And lastly, somebody who is slow to learn and quick to forget. So he has two negatives, a double negative. This type of person has a bad portion. We’re not criticizing them. People are born with certain cognitive abilities, and this person, unfortunately, is born with the inability to understand things and with a bad portion. This person is really facing a difficult situation where he doesn’t really have the major potential to become a Talmid Hacham (Torah scholar). But, of course, everybody, with work and hatmada and diligence and ratzon (will), has the ability to become something if they really put their mind to it.