This is one for Jonny methinks.
The true punster’s mind cycles through homophones in search of a quip the way small children delight in rhymes or experiment babblingly with language. Accordingly, the least intolerable puns are those that avoid the pun’s essential puerility. Richard Whately, Archbishop of Dublin, was a specialist. He could effortlessly execute the double pun: Noah’s Ark was made of gopher-wood, he would say, but Joan of Arc was maid of Orleans. Some Whately-isms are so complex that they nearly amount to honest jokes: “Why can a man never starve in the Great Desert? Because he can eat the sand which is there. But what brought the sandwiches there? Why, Noah sent Ham, and his descendants mustered and bred.”