I think Shakespeare exemplifies the rule itself. One not understanding it is a product of a lack of context of the time around which it was released. Take a course in Shakespeare and it will be covered (I was so lucky enough take a course under an absolute expert on the topic). I can see the objection "I shouldn't have to take a course to get it", but remember we are now stuck objecting now to one of the greatest bodies of writing in European history, a body that invented the foundation of much of modern comedy in inventing the Pun.

Many scholars seriously believe Shakespeare was the only author to ever use Puns effectively. I think that's an over-reach.