Back in the 1960s and 70s, my mother became utterly convinced that public schools are very poor quality. She embarked on a quest to identify the “best” school in the area, and went out of her way to take me there. I do not recall ever going to the local school. After my first few days at a new high school, I told my mother that it was not academically challenging enough, and she pulled me from the school.
Then I went to France as an exchange student, and had quite a rude awakening. American schools did not even approach the rigor of French schools. After spending my whole life easily sailing through school, I found myself behind my French counterparts, struggling to catch up. In college, I finally learned the material that French high school students already knew.
And yet, American education keeps getting dumbed down.
Formal schooling is overestimated. Greatly.