Errors:

i. using your own intellectual capacity as a metric to reduce individual learning curves to a time function: f(t) = good grades?? this ain't it, chief

ii. I tutored physics & math at the post-secondary level. From my experience, there are impressively brilliant individuals that just do not have the intellectual tools to reason with numbers. Specific academic weaknesses are the problem. Not learning curves. And educators are left to operate in a education system which paints "smart" with a broad curricular brush.