THERE IS A DRESS, or maybe I should say a gown, that has been haunting me from a Venetian shop window. A long fall of hand-painted velvet, it mingles gold, copper, rust, blue sliding into an undersea green so dark it is almost black. Its mysterious patterns evoke waves, ripples, points of light reflected on water, hidden depths. A matching bolero jacket has short, winglike sleeves. It costs 900 euros, or about 1,200 dollars.

It will never be mine. Even if I could afford it, I have no idea where I would wear it, or how to pull it off (I suspect you would have to be at least 5’10” or willing to wear disagreeably high heels). Its artistry and elegance seem a remnant of another era, or perhaps an emanation from some extraterrestrial sphere whose denizens swim delightedly in radiance and color.

I don’t like the word luxury because it has become a snob term, an advertising come-on, yet I am drawn to what it once conveyed: a lavishness and invention beyond the ordinary. I am antediluvian enough to frown upon jeans at the opera or theatre or ballet: yes, even if they are free of gimmicky stitching, even if they’re pressed, even if they are worn with a satin shirt. But do I insist on full evening regalia? Nope. I’m not an enemy of dressing down. It’s more that I find enormous pleasure in dressing up.

Most modern fashion conversations aren’t about that. In my former life as a magazine writer and editor, I found that women have little time, money, or inclination to get fancy with their wardrobes. What they want to know is how to convert what they’ve worn to work into something that passes muster at night. Intensifying that bias is a pervasive fear of overdoing, of looking as if they are trying too hard. Better to under-dress. It’s cooler, more ironic.

I understand the time crunch, the irony, our current uniform of blazers and pencil skirts, jeans and sweats. Reality bites down, hard, on evening attire for almost anybody except actresses who hit the Red Carpet on a regular basis during awards season (maybe “my” dress will be snatched up and borne off to the Oscars by a discriminating starlet passing through Venice). But the avoidance of dressing up is a loss, psychologically as well as aesthetically. Disguise is what we get out of it: a chance to present a heightened, perhaps unfamiliar version of ourselves. It’s a form of play.

IT STARTS, I guess, with trying to look older: delving into your mother’s closet and making believe you’re a big lady. I don’t remember doing the iconic girlhood walk-around in mom’s high heels—I don’t think she wore them much—but I do recall reveling in her jewel box, and my grandmother’s, burying my hands in pearls and beads as if in sand, or dragon’s treasure. This fascination with baubles was odd, because I was hardly a budding fashion maven. I was fat, shy, and rural. Growing up in the country, I had few occasions to dress up. My mother did, however, get me “city” coats for trips to Manhattan to see the dentist, or the ballet. One was dusty rose wool, the other brown tweed, both double-breasted and trimmed in velvet, with—get this—matching hats, little bonnets that tied under my chin. They camouflaged my dumpy self.

There was also the annual metamorphosis of Hallowe’en. One year I wore my mother’s wedding dress, which she cut down, unsentimentally, for me; other times I was fitted out as a Spanish dancer (with fan, comb, mantilla) or Dutch girl (the lace cap had yellow yarn braids attached). In all cases there was the bonus of dark red lipstick. It hardly mattered that I looked not at all like an adult woman getting married or a girl from another country. I wanted to be grown-up; I wanted to be exotic; I wanted to be noticed.

Little girls who like clothes are often brazen about their desire to be noticed. Fancy is not a dirty word. Sparkly is good, shiny is better; lace, velvet, pearls, tiny buttons, puffy skirts…. I’m not talking about the horrific spectacle of six-year-olds in beauty contests, à la poor JonBenét Ramsey, made up and flouncy and preternaturally confident. I’m talking about glittery headbands on tousled heads, overalled tomboys in sparkly pink sneakers, fairy wings on tee shirts. Kids that age can be girlish and boyish.

This may be a game of let’s-pretend, but why do we have to (permanently) grow out of it? Too often adults act out a different sort of masquerade, more burka than ball gown: plain, black, nondescript. But secretly, we want to be the Queen of the May. In dressing up, we get both the safety of disguise and the satisfaction of drawing attention. Fashion doesn’t get much better.

VENICE, WITH ITS MASKS and carnevale costume madness, is a natural place to ponder camouflage and revelation. And so, soon after arriving this winter, I headed for its costume and textile museum, Palazzo Mocenigo, to see “Elegance in Exile: Fashion and Costumes in the Age of Diaghilev.” Drawn from the collections of Russian émigré Alexandre Vasiliev and Italian dancer and choreographer Toni Candeloro, the exhibit had none of the heat, buzz, or surreal juxtapositions of last year’s Alexander McQueen show at the Metropolitan Museum of Art. Yet in its own way, it was provocative.

Must-see lists in Venice seldom even recognize this palazzo; thus, there was a dusty, moribund air to the premises as I entered on the ground floor: a lone ticketseller and a couple of sad posters. Upstairs, things became significantly ritzier. Down the length of the regal central space—mirrors and portraits galore—chandeliers lighted a succession of evening dresses and cloaks from the teens and 1920s. Beaded and embroidered, furred and fringed, these garments undoubtedly killed the eyes of ill-paid seamstresses and tailors, but they also signaled the glamour and drama of a period in which wealthy women made grand entrances at cocktail parties and really dressed for evening.  Think Downton Abbey.

Off the main room were smaller chambers where the mannequins—their clothes color-coded to the walls—stood alongside an enormous bed or in the midst of an old-fashioned bathroom with double sinks and linen towels at the ready. I had the feeling of wandering through a private house, and in fact, this was the home, from the 1600s on, of an eminent local family: Over the centuries, the Mocenigos gave seven doges to Venice’s oligarchic ruling class.

In the last rooms—talk about disguises—came boldly graphic, brilliantly colored, enduringly avant-garde costumes from Diaghilev’s Ballets Russes and the Paris Opéra, designed by émigré artists like Natalia Goncharova, Léon Bakst, and André Derain. It’s interesting that all three were serious, often visionary painters as well as theatrical designers. These costumes—with their scale and power, brash gold curlicues, mixed folkloric patterns, and eclectic influences—sit on the line between fashion and fine art. The two didn’t used to be so separate.

There were also, to my balletomaniac glee, glass-topped cases crammed with dance-related memorabilia: notes and sketches for costume designs, Russian tsarina headdresses hung with pearls, studio portraits of the likes of Anna Pavlova, and a photo of one eminent Russian ballerina in a wretchedly flat-backed arabesque that would not pass muster on stages today.

AS BALLET TECHNIQUE has changed, so have tastes. These clothes and costumes are a hundred years old, within my grandmother’s generation and even encompassing a bit of my mother’s. Many of them are looser, moving out of the corset era: Bodily liberation is at hand.  Yet the sweeping hems, elaborate fabrics, and labor-intensive details seem impossible today.

Clothes, of course, especially dressy ones, are always laden with cultural messages. Back then, what you wore signaled class and income, the unmistakable difference between worker and client, creator and consumer (and man and woman: my husband commented that in a costume like this a woman could scarcely do more than “just stand there”). Nowadays, in the age of Uniqlo cashmere and understatement, the markers are often more ambiguous. You must have finely tuned fashion radar to detect the high-end details—designer shoes and handbags, fancy watches, expensive blond streaks—that distinguish one jeans-clad or little-black-dress-wearing person from another.

This, I suppose, is democracy in action. It’s parallel to the shift from actually going to the Metropolitan Opera House to schlepping to the local movie theatre to watch a real-time transmission of a Saturday matinee. Now, I’m a big fan of Uniqlo and of The Met: Live in HD. But I mourn the massification and casualization of fashion, however practical, because it makes the act of dressing up almost obsolete. Fancy clothes aren’t just about wealth and display. They are also about self-creation, and splendor, and vision.

THE GOWN in Venice—which evokes Kandinsky, Klee, or Sonia Delaunay more than McQueen—is clearly a descendant of the dresses, capes, and stage regalia at Palazzo Mocenigo. Its creator is Hélène Ferruzzi, originally French, now Venetian, and fusing the chic of one with the vivacity and mystery of the other. Fabric is her canvas, and her patterns resemble everything from exotic alphabets to ancient mosaics, from circles as winsome as a child’s balloon to water that trembles and shines. The colors and textures may alternately suggest the patina of age or the immediacy of the freshly painted.  Her shop, hung with velvets and silks and linens (see photo of me there, below), is an Aladdin’s cave. The word raiment, from the Old French meaning array, comes to mind.

Reader, I tried on the dress.

Slipping into it, I felt the cool, sensual touch of the silk lining. But when I first gazed at my reflection, my posture was hunched, anxious, slightly abashed. The gown hung on me almost sullenly, as if it knew I was embarrassed by its richness.

Hélène, standing by, told me to hold myself like a dancer. When I straightened up, the dress came to life: As I turned and swayed and let the fabric move, the pattern too seemed to undulate, as if it were born of water rather than cloth.

I don’t want to get pretentious about this. On one level it was simply an act of frivolity and fantasy; a woman trying on a dress that was, in every sense, too much for her. But was it, really? Isn’t too much what we say to ourselves when we are afraid to leave what is familiar?

It struck me that dressing up is partly about what the clothes ask of you. It is a more intimate transaction than you might think, enlarging the private, idealized vision of yourself as well as altering your outward appearance. “It is almost as if the dress demanded that I be more,” I wrote to Hèléne afterward. “Not only to stand like a dancer, but to believe in myself.”

People on the street stopped and looked at me inside the shop. There was no place to hide. I had to accept the eyes upon me, the brilliance that drew them. To my surprise, I liked it.

The gown returned to its hanger in the window; I climbed back into my usual blacks and grays: both relief and anticlimax. The dress had changed me. Although it would not live in my closet, it would survive in my mind, a marker for the part of me that breaks the rules of discretion—the part of me that unashamedly loves her moment of glory.