Timing is everything. For 51 weeks of the year, an early stroll through the center of old Pamplona, in northern Spain, is a sedate activity. I exchange greetings with passersby. I savor the drowsy sights, sounds and scents of a city rousing for the day ahead. Ah, but then I think about the other week.

If I make the same morning ramble between July 7 and 14, the streets will be crowded, soused in noise and drunken fervor, and I will be risking life and limb. At precisely 8 a.m., the clock of the Church of San Cernin strikes and a rocket is fired into the air. At that signal, the gates of a corral are opened, unleashing a herd of bulls.

Standing within the corral, which on this day serves as a car park, I conjure the tumult of the one week of the year when all is not calm. I imagine the scene from the perspective of the bulls.

You were brought here from the serenity of the countryside, and now you have been abruptly released onto a steep city street. There are walls and barriers on either side. Ahead is a mob of people, most of whom are dressed in white shirts and pants with red neck scarves. Your instinct tells you to run, and your only option is to gallop up the hill toward the rowdy tide of humanity.

Strolling up from the car park, I reach the spot at which the bravest — or dumbest — people take up position on those fateful July mornings. Now I switch my perspective and imagine the bovine stampede heading toward me. There are 12 animals in all: six steers (castrated and relatively benign bulls who lead the way) and six fighting bulls rippling with testosterone. The hooves thunder toward me, and I have no option but to turn and run. A crowd of 4,000 people blocks my escape route.

The Running of the Bulls (encierro in Spanish), which forms the centerpiece of Pamplona’s festival of San Fermin, goes back to medieval times, though its global fame is largely thanks to Ernest Hemingway, who featured it in his 1926 novel, The Sun Also Rises.

Since then, local runners have been joined by considerable numbers of foreign students and adrenaline-seeking tourists. There are no entry fees, no disclaimer forms. Prospective participants merely climb the barriers onto the streets and there they are, in harm’s way.

The route from the corral to the bullring (where the fighting bulls will be killed by matadors later in the day) covers a distance of 848.6 meters (half a mile). The chaos of the daily run lasts for around four minutes, leaving in its wake silence, a handful of injuries (mostly caused by the elbows of other runners) and, occasionally, death.

In the past 100 years, 15 runners have been fatally gored, the most recent being a young Spaniard in 2009. The vast majority survive unscathed, especially if they adhere to the cardinal rule: Stay motionless until other runners say it’s safe to get up. The bulls are attracted to movement.

Continuing my peaceful walk, I remember the words of my friend Francisco, who only ended his annual participation when he became a father: “The ultimate is when you run in front of the bulls close enough to feel their breath on your trousers. Afterwards you are a giant.”

I imagine that fleeting thrill. The bulls behind me, their lethal horns lowered, their nostrils flared. At the last moment I keel over the barrier to safety and the bulls thunder on. Could I ever do it? It would take courage — and exceptional timing.