You've had enough. You're ready to escape a gathering, but, in many countries, manners dictate going around the table to kiss everyone goodbye. With a certain type of folks and level of chaos and inebriation, these goodbyes can take ages.
The Germans have a much less kissy-kissy culture than many of their European counterparts, so it should come as no surprise that they also offer a more efficient farewell solution. Here, it's acceptable to simply rap your fist on the table to announce your departure. That little knock counts as the goodbye for everyone — no individual kisses, hugs, promises to get together again soon, drunken propositions or tears. You're out of here, Auf Wiedersehen.