Many higher beings have commented that Human Beings' need a sense of humour or they would never make it through a complete solar rotation.
Other beings have achieved a semblance of a sense of humour, some from an extensive undercover study of humans, others from an extensive under skin study of humans; which was promptly put to a stop and covered up by yet another cholera outbreak.
One of the guilty, Vivian Sectionist (a Taxi Derma from the planet Stuff), managed to escape his captors by simply booking a place at the Restaurant at the End of the Universe and ordering several cocktails with amusing names to test drive his newly acquired sense.
Unfortunately Commisioner O'Leary of the drunken irish stereotype planet was also enjoying a number of hilariously monikered cocktails at Milliways several years (from his point of view) before his future nemesis committed his hateful crimes.
During a peculiarly long session of the biscuit game Sergeant O'Leary - as he was known at this point in his own personal timeline - discovered the enormity of Vivians' crimes; knowing full well that the inhabitants of Stuff have no sense of humour whatsoever (particularly the Taxi Dermas, Taxi Mentals and all who lived on the shores of the Taxid River).
On his return to his present O'Leary constructed an intricate plan to trap Sectionist before he could commit his crimes against humanity and therefore trapped him in a temporal loop where he had nothing to do but suffer the effects of a hangover from the imbibement of a large number of cocktails which he no longer found amusing.
O'Leary was duly promoted to Commissioner enjoying a long and illustrious career until the Time Police caught up with him on his death bed and stripped him of his experiences and forced him to relive his life as a tour guide for Uranus dealing with a number of school partys. His sense of humour tested to the limit he was glad to be relieved of his life by an intrigued humourless Taxi Derma in a dark alley during a cholera outbreak.
The timelines are re-ordering themselves to this day.