I constantly memorize the Quran, but I quickly forget it?

The Quran is the facilitated word of Allah for remembrance. To avoid forgetting its memorization, you must regularly recite and review it daily, as the Prophet said: "Attend constantly to the Quran, for by Him in whose hand is the soul of Muhammad, it is more liable to escape than camels from their hobbles." Secondly, supplicate to Allah to make it easy for you and to firmly establish it in your heart. Thirdly, strive in supererogatory acts of worship and keep away from sins, as this is one of the most important reasons for success and facilitation.