I had no idea what the Met Gala was until yesterday, and I am disappointed in everyone again. Wear fab clothes. Go to museums. Sure, that's great. Rich people parties as spectacle for US culture? I'm not really a fan.
The library is better for dressing up imo, because if you do so at the art museum they get angry when you take photos in front of the art. At the library, if you want to take glamour shots in front of a bunch of books, the librarians are just like "hell yes!"