Zoolander is twenty five, and the number lands strangely, because the film has never really aged into a classic so much as refused to leave. It gets quoted constantly by people who have not actually watched it in a decade.
It arrived on September 28, 2001, two and a half weeks after the September 11 attacks, into a New York that no longer looked the way the film had shot it. Ben Stiller had the Twin Towers digitally removed from every background shot of the skyline. They stayed out of the picture for fifteen years and were only restored for a Blu-ray release in 2016. Almost nobody noticed the absence at the time, which was precisely the intention.
Derek Zoolander existed before the film did. Stiller and Drake Sather built him out across a pair of shorts made for the VH1 Fashion Awards, and you can feel that sketch DNA in the finished picture, which keeps threatening to collapse into a run of bits and then, oddly, does not.
What holds it together is that the satire is genuinely aimed. The jokes about the fashion industry are affectionate enough, but the film is much harder on the machinery around it, on a business that treats beautiful and empty people as raw material to be used. Will Ferrell's Mugatu is the clearest statement of that, and the reason the comedy has a floor under it.
It runs eighty nine minutes and does not waste any of them. If you have only ever met this film through the quotes, what is underneath them is weirder and far better built than the quotes let on.