Well, if we do actually benefit from learning and reading the Torah even if we don't understand or remember it, then what is the point of understanding it and remembering it?
Simple. The person who learns and understands is able to connect to a far loftier reality of the Torah than one who learns without understanding. This is so much the case that the learning of the one who understands is like unto the soul compared with the body of the learning of the one who does not understand. This relationship plays out further in that the learning of one who understands the sod, the secrets of the Torah, is similarly far beyond (as the soul to the body) the learning of someone who understands only the p'shat, the simple/basic understanding.
He goes on even to list a number of levels of sod, of hidden understandings and meanings, including the understanding of the secrets of the letters, and above this the understandings of the secrets of the permutations of the letters, and above this the understandings of the secrets of the names of HaShem, and above this the understandings of the secrets of the permutations of the names of HaShem. [He warns though that while it is permitted to learn this level for the sake of growing closer to HaShem, it is forebidden to use this knowledge actively as most of this knowledge is lost to us and it is impossible to make use of it without causing dire harm to oneself [and the world.]]