The Messenger of Allah (S) said,
“The best fathers are those that teach.”

Memorization of texts was the traditional way students all over the Muslim world would retain the knowledge they were seeking. There are many stories and sayings of the scholars emphasizing the need to have the text memorized, but there is a famous one of Imam Al Ghazzali with which many people are familiar.
Imam Al Ghazzali had spent two years transcribing texts that he would be using in his studies. He then traveled with this library when brigands attacked the caravan. They began to take his books because books in those days were very valuable. He asked one of the brigands to at least leave his books and not take away his knowledge. The brigand responded, "What kind of knowledge is that if a person like me can take it away from you?" Imam Ghazzali realized then that Allah (glory be to Him) had made him say that, and he resolved to memorize any knowledge he pursued in the future.
Imam Al Shafi' also stressed the importance of memorization, and there are many amazing stories about his power of memorization. He has some lines of poetry to the effect of, "My knowledge is with me wherever I go, and it is not in my trunk at home," meaning that his knowledge is not only recorded in the books of his library but also imprinted on his mind and heart.
Traditional studies in the classical Mauritanian system are not bound to a classroom setting, but are highly individualized. Each student studies one subject with the Shaykh individually, with daily study assignments. The teacher writes the lesson text on the students' writing tablet. The student then will spend the day memorizing the text of that day's lesson. The student will only have one subject until they have finished that text. They will then proceed to another text at the Shaykhs' direction.
Educational materials are quite simple: a pen, black ink, and the "Lauh", a wooden writing tablet, often coated with a thin layer of white clay, upon which Qur'anic verses or other texts are written.
Paper making consumes a great deal of water, and is not practical in in arid lands. In a poor country, imported paper is very expensive. Pens are cut from the stalks of a local reed or shrub. Ink is made of water, soot washed off cooking pots, and vegetable gum. With use of the Lauh, no notepaper, notebooks, or blackboards are required.