Herbstzeitlosen refers to autumn crocuses or meadow saffron. It's a beautiful and somewhat rare word for a flower that blooms in autumn, often mistaken for a true crocus.
In the song, these flowers are mentioned as
Udo Jurgens sings this as a wry little fable about how life keeps handing you the same bittersweet bouquet.
The verses tell two mirror-image stories: getting fired for chasing the boss's secretary, then finding a new woman on the rebound (who, in a running joke, turns out to be called Dieter). Every time something falls apart, the chorus shrugs it off with mock politeness: "Thank you very much for the flowers, how kind of you." It's the sarcastic reply of someone who has just been let down, said with a smile instead of a scene.
By the closing verse the flowers become a real metaphor. Roses, mimosas and autumn crocuses all bloom and fade, and the singer decides losing is just part of the deal. The song's charm is in that resigned, cheerful tone: bad luck in love and work is treated as ordinary weather, not tragedy.