"LESS" is the opposite of "MOR". "OFF is the opposite of "ON"
Therefore, the double negative "LESSOFF" actually has a similar meaning to "MORON".
"LESSON" acutally has the opposite meaning of "MORON" by the same logic, as it is a single negative.
The only way to deal with this is to treat everybody as a moron till proven otherwise.
How? Explain things to them like you would a child and hope they dont make a mistake