Memorizing the New Testament - Do Kids Really Memorize the Entire Koran?

I made a video about how to memorized the New Testament and suggested that 21 years is a good goal for most people who want to try (https://www.youtube.com/watch?v=EJtG3nsjeWQ).   One of the comments was both encouraging and a bit critical at the same time.  The criticism was not necessarily at me as it was about people who don't memorize or who don't think they can do it.  The commentator claimed that Muslim kids were memorizing the entire Koran in Arabic within three years, so we can if we try.

So I looked up on the internet (what a marvelous tool) and found that there were indeed kids who memorize the entire Koran when they are young.  Some Muslims believe this is a miracle of Allah, others just believe these are smart kids.

Here are some of my thoughts:

-I admit it is an amazing accomplishment to memorize so much at such a young age.
-I am not so sure that kids who do not speak Arabic understand as much of it as is told us.  However, they have a lot of understanding because children learn languages far easier before puberty (and without accent) than those of us who are past puberty.
-The Koran has 77,701 words in it; the New Testament has 138,020 words in it.  So the New Testament has almost twice as much material to memorize.  When anyone is trying to keep up with past memory verses as well as memorizing new, this will make a big difference.
-It is possible to memorize every verse in the New Testament, make such boasts, but in fact only remember a small portion of it because people will forget verses that are not repeated over and over...and who wants to repeat over 70,000 or 138,00 words by rote each day, or week, or even month?
-In eternity, God will not ask us how much of the Bible we memorized (although it is a great tool), but how we served others.  In the larger scheme of things, I would rather be credited with helping people live better lives than memorizing the entire Bible and/or the Koran.  But having stated this, I do want to memorize a lot because I teach the Bible and find it very useful in my ministry of serving others as long as it is used to serve others and not to draw undo attention to myself or my abilities.