All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The scholars differed in opinion on the ruling on forgetting what one memorized from the Quran –out of laziness and negligence without any sound excuse. Some scholars considered it as a grave major sin, while others considered it as a minor sin. However, some contemporary Sharee’ah institutions are of the view that it is not forbidden at all. The Fatwa of the Permanent Committee reads:
“It is not befitting for anyone who memorized the Quran to be negligent about its recitation, nor should he be negligent in revising it. Rather, he should recite a portion of it daily in order to help him perfect it and not forget it, while seeking the reward and benefitting from its rulings: both in regard to belief and actions. But if someone memorized any part or portion of the Quran and forgot it because he became busy or due to negligence, then he is not sinful. The texts with warning against forgetting what one has memorized of the Quran are not authentic.” [End of quote]
In any case, if what you forgot of the Quran was before you reached the age of puberty, then according to the view of all the scholars, you are not held accountable before puberty.
We advise you to avoid whispers and thinking about what you forgot to memorize of the Quran when you were young. Rather, you should concentrate on benefitting from the Quran now and in the future.
We advise you to be keen on reciting the book of Allah, pondering over its meanings, understanding its verses, and being admonished by it.
If it is not possible to combine between the recitation of the Quran and pondering over it, then pondering over it and understanding its meanings comes in priority over exerting one’s effort in memorizing the Quran without understanding it and pondering over it.
Allah knows best.