https://www.bbc.com/news/stories-43700153
The TV movie, "The Pride of Jesse Hallam" (1981), is a fictional tale of a man who can't/never learned how to read. The link above shows how a child can "slip through the gaps" in an educational system...all the way back to the classroom. Once again, Truth Is Stranger Than Fiction.
Johnny Cash: "I'm Just An Old Chunk of Coal"