L'air du temps literally translates to "the air of the times". It's a classic French idiom that refers to the prevailing mood, style, or spirit of a particular period.
In "La Bohème," Charles Aznavour sings "nous vivions de l'air du temps" (we lived on the air of the times). This beautifully captures the essence of their youthful, artistic poverty: they had no money for material things, so they sustained themselves on creativity, love, and the vibrant, carefree spirit of the moment.
Step into the cold attic rooms of Montmartre with Charles Aznavour as he looks back on his days as a starving painter. Right from the start, he warns that anyone under twenty can't understand this era: Je vous parle d'un temps / Que les moins de vingt ans / Ne peuvent pas connaître ('I am talking to you about a time that those under twenty cannot know'). He lived in a shabby rented room, l'humble garni, with his muse, surviving on almost nothing. The reality was rough: Nous ne mangions qu'un jour sur deux ('We only ate every other day'). Yet, trading a fresh canvas to a local café owner for a warm meal felt like total victory. They would crowd around a stove to recite poetry and pretend winter didn't exist.
The real punch arrives at the end when he walks back up the hill to visit his old neighborhood. Everything has changed. The painter looks for his old studio, but plus rien ne subsiste ('nothing remains of it'). The lilacs that once grew right beneath his windows are dead, and the bohemian lifestyle he loved so fiercely has vanished without a trace: Ça ne veut plus rien dire du tout ('It doesn't mean anything at all anymore'). It is a brutal, honest realization that youth is gone, and the places that shaped you move on without you.