Decades? I missed 3 months of 4th grade. The teacher said I should be stuck back in 3rd because 4th grade had moved along so quickly. My mom said no, and put me in the 4th grade class around Christmastime.

I wasn't a day behind. The class had not advanced at all.

But I'm sure the pandemic will be blamed for school unachievement for decades. It's a godsend to the school industrial complex.