London — There is a giant mirror in my hometown in Ireland. It covers one side of a building that you must walk past to get from my mother’s house to the town center. When I was a teenager, I learned to take a different route. The mirror was always sparkling clean, a burst of reflection in the middle of a dull street. It showed me, abruptly, how others saw me.

With other, smaller mirrors, like those in my bedroom or the camera on my phone, I could prepare myself and decide my approach. But with the mirror on the street I saw myself as I was, plodding down the little hill without grace or charm. All at once I could see the truth so plainly. No matter how long I had spent applying makeup or adjusting my outfit or psyching myself up to go out, I was not beautiful.

When I was younger, I wanted to be beautiful so badly that I could taste it, and it tasted like blood. It was a hard, painful desire. I didn’t want to be cute, or pretty. I didn’t want to be more attractive to men. I didn’t want to be sexier. I wanted only to be beautiful, and the fact that I was not beautiful hurt more, not less, for the fact that I so nearly was. What I wanted was to be undeniable, to be all clean lines, to not be debatable. I wanted to be like a drawing of a beautiful woman you might do in a game of Pictionary.

I think now that I idolized beauty so much because I was often embarrassed and ashamed as a teenager and beauty seemed the opposite of embarrassment to me. To be beautiful was to have power over others. It was much more difficult to make a beautiful girl seem foolish than it was an average-looking one, I thought.