Many Arabs have memorized the whole Quran!! In most families you will always find at least one Hafiz. And usually if a father is a Hafiz, the son is as well. And among desis believe it or not you will find Huffaz. They just don't go around telling people.
Memorization might be easier when you know Arabic but it's still difficult and definitely an accomplishment. I will say that for Arabs memorization of Quran is very important, and they don't go by Surahs but by Juzz!! Their kids haven't made a start until they've memorized the first Juzz you know