The only thing that has stuck for a decade in my memory from Edith Nesbit’s classic novel “Five Children and It” is the set of instructions on how to will yourself into waking up at a certain hour. “You get into bed at night,” Nesbit writes, “and lie down quite flat on your little back with your hands straight down by your sides. Then you say ‘I must wake up at five’ (or six, or seven, or eight, or nine, or whatever the time is that you want), and as you say it you push your chin down on to your chest and then bang your head back on the pillow. And you do this as many times as there are ones in the time you want to wake up at. (It is quite an easy sum.)”

I remember being skeptical of this system as a 12 year-old—was Nesbit trying to make a joke at the expense of her “little” readers? But over the years, I discovered that if I thought concertedly about the time I needed to get up the following morning, I often woke up a few minutes before my alarm clock, no matter how irregular the hours I was keeping. Apparently, you can will yourself into waking up when you need to, along with the proven facts that you can will yourself into a better mood by smiling, and that you can will yourself into believing a placebo will help you even when you know it’s a placebo. I also think that you can will yourself into finding the exact piece of art that you’ve been looking for, knowingly or not.

Two summers ago, due to a flight-planning error, I had a day to pass in London with absolutely nothing to do. I ended up going for an all-day walk, mostly because all the Underground stations were being fixed up for the Olympics. My backpack was heavy, and my walk was aimless and depressing. I was alone and had no money to speak of—I ate four toffee-flavored yogurts because they were on sale. I walked to the palace, along the river, to the Tate Modern, and up to the Brick Lane area, where I found a lot of beautiful full-mink stoles that I didn’t have the money to buy. Finally, evening was falling, and I could start heading to the airport where I was to spend the night.

I had just turned westward and begun the slog from Brick Lane to King’s Cross when I found, along a wide, gray street, a wall of paintings by Ben Eine, the alphabet-obsessed street artist whose work British Prime Minster David Cameron had recently presented to Barack Obama. Following Eine’s letters, I found a massive weasel painted by another famous street artist, Roa, whose intensely detailed, morbid, textural, drawing-like depictions of rodents and birds had been cycling through my Google Reader for years. The weasel did not look like an etching, the way Roa’s pieces look online. I could see the powdery sweep of the fine-nozzled black spray can. I was just as tall as its stomach.

Though the beating heart of street art is its accessibility and its rejection of all kinds of formal art institutions, from schools to galleries, the works’ indivisibility from their places of creation makes them even more elusive to enjoy in person than even the most elite painting. Seen live, the weasel was beautiful, monstrous, and totally unmanageable—the kind of megafauna that prehistoric humans killed off as they developed more advanced missile technology. I could not contain my excitement and exclaimed about the piece to passersby. Looking at the Roa in the twilight did not suddenly bring my life into focus for me. It did not diminish any grander site that I had seen earlier in the city. It was not the symbol of my travels, or anything else. But it was a powerful experience.

I think that one possible key to enjoying art is allowing yourself to accept what you see, the way you would accept the 7:58 that you see on your clock upon waking when you have set your alarm to ring at 8:00. Let art be something that contains the force of that personal will. Street art like Roa’s weasel, which requires some kind of wandering and stumbling upon, is particularly apt for this kind of discovery. Art always anticipates, and it will be there when you wake. Enjoying art is an act of will: You meet it halfway with hope, and it will repay you many times over.

—Columnist Molly E. Dektar can be reached at mdektar@fas.harvard.edu.