The first fashion show Raf Simons ever saw was Martin Margiela's third collection in 1991. He was so moved he cried, and right then and there he decided he wanted to be a fashion designer, too. It was such a landmark moment for him that he claimed his own 15th-anniversary show in Paris tonight was an homage. But in fact, the designer he was primarily quoting from, in a collection that reaffirmed his status as menswear's most forward-looking practitioner, was himself.

The music by the Smashing Pumpkins included "Tonight, Tonight," which soundtracked Simons' first show in 1997. (According to Michel Gaubert, Simons' longtime musical collaborator, it was entirely coincidental that Mellon Collie and the Infinite Sadness, the album it was on, was actually released in 1995, the year the designer launched his business.) The tailoring, in which he pared away such superfluities as sleeves, is a Simons signature. He has done collections focused on white, on intense color, and on sports, all of which appeared here tonight. The pants that ended in puddles of fabric were from an old show, and the photographic collages he deployed were in the vein of another longtime collaborator, Antwerp artist/writer Peter de Potter. Above all, the model casting underlined Simons' career-long reverence for the vulnerable, transient beauty of youth, the celebration of which has been fundamental to all his collections.

But the show was far from a retrospective. "How we would be real," the words on one T-shirt, cut to the quick of Simons' obsession. He has always challenged orthodoxy, deconstructing and reconstructing in the name of the new. Here, the dominant motif was the zipper, huge industrial-looking versions that trailed down the back—and in many cases, the front too—of almost everything. The zip pulls were extended metallic strips, apparently borrowed from surf wear. Something that big begs to be pulled, and such an open invitation to revelation somehow seemed like the core of the collection.

The final outfit was a perfectly tailored two-button navy suit with a shirt and tie. No zips, no tricks. It felt like a confident, this-is-how-far-I've-come declaration. Indeed, after the show, Simons was talking about how far menswear generally has progressed during his years in business. His anniversary collection seemed intended to illuminate the possibilities that still exist, for him as much as for any other designer. Who knows, maybe there was someone in the audience who would take this show as his own "Eureka!" moment, just as Simons did with Margiela nearly two decades earlier.