U IS AN UNPLUMBED WELL

 "When Freud fled Austria after the Nazi takeover,

 the Nazis would not let Freud board the train to Paris unless he provided a statement that absolved them of any blame.

 'I can heartily recommend the Gestapo to anyone,' Freud wrote. The Nazis did not see the irony." 
- Paul Boehm

Freud looked almost relieved as he said, "We are nearing the end of this Challenge of yours ... and mine."

He looked at Mark. "Soon I will be spared your wit, half share though you have."

Mark pretended to be stabbed by an invisible sword under his heart and said,

 "Wit ... the sudden marriage of ideas which, before their union, were not perceived to have any relation."

Mark shrugged. 

"Wit and Humor--if there is any difference it is in duration--lightning and electric light. 

Same material, apparently; 

but one is vivid, brief, and can do damage--the other fools along and enjoys the elaboration."

I was afraid things might get nasty again and said, 

"The Letter now is U.  And the concept of Understanding occurs to me."

Freud nodded, 

"Odd that you mention Understanding.  I believe, Twain, that I understand your prickling words to me."

He sighed, 

"Far from being able to identify with me, many people feel threatened.  

I am a quintessential father figure. 

Many people see themselves as rebels against authority and so feel compelled to throw barbs at me."

Mark winked at me and jabbed a thumb at Freud.  "And he's humble, too."

Mark smiled, 

 "I always try to acknowledge a fault frankly.  

This will throw those in authority off guard and give you time to commit more!"

 Freud said, "Do you believe half of what you say?"

"If I don't, I lie."