Vacille means to 'waver', 'flicker', or 'falter'. It beautifully describes an unsteady movement, like a candle flame about to go out or someone stumbling.
In the song, the artist poses a deep question about happiness, describing it as a fragile thread. He asks what happens "Quand il vacille et se brise" (When it wavers and breaks), using this word to paint a vivid, poignant picture of how delicate and unstable joy can be. It's a fantastic, evocative verb to learn for expressing nuanced emotions.
This song feels like a conversation with a parent when you're feeling lost. The singer asks their mother a series of big, difficult questions about life. It starts with a very direct one: "Où va-t-on / Quand on n'a plus de maison" (Where do we go / When we no longer have a home?). This sets the tone for a song full of searching and uncertainty.
The questions keep coming, touching on happiness, dreams, and doubt. The singer wonders where happiness goes when it breaks, describing it as "ce fil fragile" (that fragile thread), and asks what happens to "les rêves qui s'enfuient" (the dreams that flee). But the chorus offers a simple, powerful answer. Beyond the storm, there is "de l'amour, de l'amour, de l'amour" (love, love, love), and after the sky opens up, everything becomes calm and will be okay.