What is the meaning of the Hadith: "If the Hafiz of the Quran recites it during the night and day, he will preserve it, and if he does not, he will forget it"?

The prophetic hadith, "The example of the companion of the Qur'an is like that of a tethered camel. If he tends to it, he holds it; but if he lets it loose, it escapes," was narrated by the two Shaykhs (Al-Bukhari and Muslim) from Ibn 'Umar. Muslim added in another narration: "And if the companion of the Qur'an stands (in prayer) and recites it by night and day, he remembers it; but if he does not stand by it, he forgets it." This hadith indicates that if the companion of the Qur'an commits to it and perseveres in its recitation, he will not forget it, but if he abandons its recitation, he will forget it. The term "companion of the Qur'an" refers to its memorizer and one who regularly recites it.