What are the causes of severe forgetfulness and sadness, what is the interpretation of the feeling of spiritual stagnation and negligence in prayer, and can the correct way of performing ablution and prayer be explained?

Error and forgetfulness are part of human nature. Allah has absolved this Ummah from accountability for them. Forgetting memorized material often arises from insufficient revision, and repeated revision is necessary. Moreover, sins are among the causes of forgetfulness, because knowledge is light, and the light of Allah is not bestowed upon a disobedient person. The sin of a follower (ma'mum) may even affect the prayer leader (imam). Therefore, continuous revision, fearing Allah, and supplicating with "O Allah, remind me of what I have forgotten, preserve for me what You have taught me, and increase me in knowledge" are required.