Perhaps, the reason is the onset of the Spring after the deadly winter that makes people lighthearted and joyful or perhaps it is the shift from the Julian calendar to the Gregorian calendar in the middle ages.
There could be “cruel” jokes like stirring a spoonful of salt instead of sugar in a cup of tea or setting up a dinner date with a friendly couple who could find the apartment locked, only to be treated at a nearby restaurant a while later. If all this is meant to lift people out of the drudgery of their daily lives, there should be nothing to complain about
