At the time, I had thick black spectacles, braces, a parental ban on anything skimpier than sleeveless tops, a free book bag from the library and something in the vicinity of four friends in school.
So I wasn't exactly jumping at the idea of a long, social night where all the popular girls would pose for photos and sign autographs before leaving when their boyfriends came to pick them up and the nerd kids would stay in their seats, picking at their food.
Where most of the other girls went to Daniel Yam to get hundred-dollar, jewel-toned gowns in shimmering fabrics, about a week before the thing, my mother dragged me to Metro, where most of the shoppers were in their forties.
Everything was dowdy and baggy and too old for me, and I tried on piece after piece feeling more and more wildly desperate.
And then, we saw the dress.
It was a blue, paisley-print, gauzy-hippie wonder of a thing, with long sleeves that hung like bells and an asymetrical hemline. "You look like Janis Joplin," my mother told me wonderingly when I skipped out of the changing room, trembling in anticipation.
And did I ever want to look like Janis Joplin! The cool, devil-may-care singer with a voice like scraping steel who marched to the beat of her own drum. The rockstar none of my classmates actually knew or cared about because Vitamin C was far more fashionable that year, but whose fashion sense would, no doubt, imbue me with a bohemian confidence.
We turned together to look in the mirror. It was far too big, hanging off my shoulders like I hadn't grown enough courage to pull it off.
I wore a long, plain, stretchy black dress instead because it was "classic" and modest and cost only $50. I had fun anyway, my four friends and I danced crazily and none of them made fun of me when I told them I was actually wearing shorts under my gown (a throwback to school when all the girls wore shorts under their uniforms for modesty).
That Janis Joplin dress, however, has never left my memory. And finally, last month I saw it, reincarnated in pink, hanging off a model in Esprit.
I couldn't believe my eyes, it was like waking up from a long, vague dream and seeing the contents of it standing in full colour before you.
I gathered it in my arms breathlessly and ran to the changing room and when I pulled it over my head and stared in the mirror, I had to smile.
It finally fit.
Paisley dress - Esprit. Cutout sandals - Dr Martens
Ring - Diva. Earrings - Topshop.