There are two categories of people with regard to Quran memorization. The first group seeks to make the act based on personal interest and spiritual gains. These people can start the memorization process from every part that they like and no special sequence is recommended.
The second category is related to those who want to participate in Quran memorization competitions, tests, and circles. This group needs to memorize the verses and Surahs according to a special sequence and plan. This is because sticking to order is the principle of memorization and if we disturb the order, the structure of memorization will also be undermined.
Children can start the memorization process from the 30th Juz (part) but adults can do this from the first Juz. Many masters believe that the 30th Juz is the gate to enter memorization of the Quran, however, they recommend people go immediately to the 1st Juz after its completion.
One of the questions that arise is why some individuals abandon the memorization process after confronting the 1st Juz? This is especially true for children as they are trained based on Surahs in the 30th Juz and when encountering the 1st Juz, become afraid. This is while memorizing a Juz is simpler than numerous smaller Surahs. The problem is that individuals are trained based on Surahs, not on lines. Children will face no problem in memorizing Surah Baqarah if they are trained based on lines.
Meanwhile, some other experts believe that the memorization process should start from the last five Juzes which start with Surah Muhammad. Their reasoning is that these Juzes and chapters include more Islamic knowledge and concepts.
There are also some other masters who point to the hard task of memorization of Juzes 20 to 30 at the end as they believe the brain of memorizers may be tired, recommending individuals to do this part first. Although some other experts do not share this belief. A point that all masters agree on is that memorization should have a determined.