Be nice if we at least encouraged schoolaged kids to be able to recite the Constitution.
I find your assertion that 'many muslims' can recite the Quran by age 12 to be specious. In order to memorize the Quran one would need to know how to read. Many Islamic countries do not allow female children to learn to read, so that would mean that only men have this ability and that would be only if they could read or if someone who could read fed it to them on a regular basis.
According to historian Donald Quataert, general Muslim literacy rates were only 2 to 3 percent in the early nineteenth century, and perhaps 15 percent at its end. The vast majority of Muslim women remained illiterate well into the twentieth century. Prior to 1840, an average of only eleven books a year were published in the imperial capital of Istanbul.[2]
Muslim Statistics (Education and Employment) - WikiIslam
Somehow I don't envision the lonely goatherd sitting out on the hills memorizing the Quran.
As to memorizing the Constitution, I find your assertion to be complete bullshit. One segment of American society, after being here for 200 years, has refused to learn to speak correctly the English language. I don't see anyone being able to require them to memorize the Constitution.