Aquarium literally means "aquarium" in French. While it might seem like a common word, its use in this song is quite unique and metaphorical.
Alizée sings, "Vivre en aquarium me rend triste" (Living in an aquarium makes me sad). She uses the image of an aquarium to represent a feeling of being trapped, observed, and isolated in a relationship that is suffocating her. This unexpected and poetic use of a simple word makes it particularly engaging and memorable in the context of the song's theme of a fading love.
A Cause De L'automne paints autumn as both a backdrop and a culprit. As the leaves drift through dark streets and colors fade, Alizée’s narrator feels love slipping away just as quickly. She blames the season for her urge to run, comparing her relationship to living in an aquarium, beautiful yet suffocating. The chill of fall becomes an easy answer for every goodbye, every hidden feeling, and every lie that piles up like fallen leaves.
Rather than a simple breakup song, it is a poetic reflection on how changes in nature mirror changes of the heart. The mood echoes French Symbolist poet Verlaine, suggesting that melancholy is almost inevitable when summer warmth gives way to autumn gloom. In just a few verses, Alizée turns crisp air and muted colors into vivid symbols of fading romance, making listeners wonder if it is really the season’s fault—or just our own fear of love’s impermanence.