Melancholisch means 'melancholy' or 'melancholic'. It's a more sophisticated and less common word than simply 'sad', suggesting a deeper, more reflective kind of sadness.
In the song, it describes the feeling of growing up and realizing that things aren't as they used to be. The line "Und manchmal wirst du melancholisch im Straßenlaternenlicht" (And sometimes you become melancholic in the streetlamp light) beautifully captures a moment of quiet introspection and longing for the past, making it a very evocative word.
German rock band AnnenMayKantereit delivers a painfully honest look at your early twenties in "21, 22, 23". The track tracks the slow slip of time as you count up the years: "Und du wirst 21, 22, 23 / Du kannst noch gar nicht wissen, was du willst" ("And you turn 21, 22, 23 / You can't possibly know what you want yet"). Instead of big life plans, the lyrics focus on university students drifting through everyday German youth culture, specifically "zwischen Kneipen und WGs" ("between pubs and shared apartments"). In Germany, a WG (short for Wohngemeinschaft) is the classic student flatshare, a place where people sit around waiting for something to happen while avoiding real adulthood.
There is a great, blunt humor in how the lyrics call out self-defense mechanisms. To protect yourself from failure, "du hältst deine Träume absichtlich klein / Um am Ende nicht enttäuscht zu sein" ("you keep your dreams intentionally small / So you won't be disappointed in the end"). Whenever anyone asks about the future, you blame outside forces, order another beer, and shrug: "Hauptsache nicht Mitte 30" ("Just not in my mid-thirties"). It is a song about getting slightly older, dancing a little less freely than you used to, and dreading the day you actually have to grow up.