One of the drs I used to work with spoke fluent German.
He recounted a story about being on holiday over there for a couple of weeks and the first night he rearranged the itinerary which was pinned to the wall and sat back and enjoyed the resultant confusion over the next few days.
Also on the first day he suffered from the 'towel reserves sun lounger' concept, so that night he wandered out and put a 'broken, do not use' (in German) sign on one of the loungers. And each day he went out to the pool and set himself up on it while everyone eagerly waited for it to collapse under him.
And his final coup de grace was when a group of them were happily slagging him and all English folk off, and he turned round and spoke to them in perfect German.....
He had a whale of a time