Einwegmomente is a compound word that literally translates to "one-way moments." It's a unique and evocative term that isn't commonly found in everyday German or song lyrics.
In the context of the song, it beautifully captures the fleeting nature of life and experiences. Bosse uses it to emphasize that every moment is unique and unrepeatable, urging listeners to cherish them because "nichts ist für immer" (nothing is forever).
Bosse wrote this one about the moment you realise something has ended. The first verse moves quickly through the markers of a German youth: the years going by, childhood closing, friends getting older, a graduation ball, long drinks emptying while your head fills up. Then comes the line the whole song rests on, that you only ever work out what something meant to you at the point of saying goodbye.
The chorus turns that into an instruction rather than a regret. Dance like it is the last dance, kiss like it is the last kiss, because nothing lasts forever and everything only happens once. It is a song that has been sung at a lot of German leaving parties and weddings for exactly that reason.
The second verse widens it out. David Bowie and Amy Winehouse are named as proof that even the best of it passes, and smaller endings sit right beside them: a holiday finishing, a suitcase being packed, the hangover that follows the dream. Bosse calls them Einwegmomente, single use moments. The bridge just asks the question twice over, why we notice only at the goodbye, only at the wave, how good it actually was.