English state education between the late 1880s and 1914 ended at age 14, many teachers taught the farmers sons (lucrative) and used the sons of the labourers as whipping boys (source, my father's memories of the time), and the military definition of literacy at the time was "able to write own name".

Sure they all knew what they were getting into. They could figure out the posters on every wall.

Oh, wait a minute, THAT was the propaganda.