Everyone is capable of, and can benefit from, mathematical thinking

I’m far from being any kind of serious mathematician, but I’ve learned more in the last couple years of taking that seriously as an ambition than in decades of relegating myself to inferiority on it.

One of the highly generous mentors who dragged me kicking and screaming into the world of even making an attempt told me: “There are no bad math students. There are only bad math teachers who themselves had bad math teachers.”

Wouldn't it then follow that all students of the same teachers end up with the same skill level in math? Not sure that's the case.

Doesn't follow. Bell curve in, shifted bell curve out. Ideally this also tweaks the variance a bit.

In other words: Some students flourish despite their teachers, some flourish because of them.

And how would you call the students in the left tail of the Bell curve if not bad students?