“Make up a language. Sell it to a university. Use it to control students and faculty and make lots of bread and win mobs of adoring - and brain dead - fans.”
Tolkien invented Elvish, twice. Quenya, “high elven”, and Sindarin, for elven commoners.
And Entish too, which goes something like “A-lalla-lalla-rumba-kamanda-lindor-burúme”
When I was young, I and some friends decided Pig Latin was a useful language to use when we did not want the other kids to know what we were saying. Are there any similar languages that kids were using when you were young?