The excitement, drama makes the Indy 500 my favorite event

But it could have been five minutes ago, the way it still lives and rises in my memory. On that last Sunday in May eight years ago in Indianapolis, I drove my rental car through the predawn darkness to the corner of 16th and Georgetown, which, to the true race fan, is the nexus of the universe. By 7 a.m. a crush of humanity had already gathered in the shadow of the grandstands of the Brickyard, the sense of anticipation crackling in the cool morning air like an electrical current.

A few hours later I rolled through the tunnel between Turns 1 and 2, parked in the speedway's infield and made my way to pit road to cover the race for SI. Once the command to start your engines was issued, I immediately felt the roar of horsepower thump, thump, thump in my chest. This was a far different feeling than one experiences when the stock cars of NASCAR fire their engines. This was more penetrating, more powerful, more soul-rattling, like standing on an aircraft carrier next to a fighter jet that is about to blast off.

After three warmup laps the green flag waved. With 300,000 fans yelling in full throat -- the Indy 500 is still the largest single-day sporting event every year in America -- the field of open-wheel cars flew along the frontstretch at 225 mph, barreling through the canyon of fans, over the red bricks at the start-finish line, past the 153-foot-tall Pagoda tower. I always take a mental snapshot of this first-lap moment because it's the most picturesque scene in motor sports, the equivalent of a Van Gogh still life for those addicted to speed.

Just then, your senses are overwhelmed. There's the high pitch of the engines, the raw speed of the cars, the smell of burning rubber and -- never forget -- the specter of danger. The assault on your senses is all-encompassing, unmatched in motor sports, and it's precisely why the Indianapolis 500, which celebrates its 100th anniversary this week, is my favorite race of the year. Actually, it's more than that: Indy is my favorite sporting event of the year. "You have to come to the track and feel the power of the cars and smell the fuel to really appreciate what makes Indy so special," says Danica Patrick, who ran in her first Indy 500 in 2005, and will start 25th on Sunday. "I tell people, 'If you come, you'll be hooked for life.' And I've never been proven wrong."

Even NASCAR drivers such as Robby Gordon, Juan Pablo Montoya and Tony Stewart who have raced in the Indy 500 will say that it's the world's greatest race. Stewart is from Columbus, Ind., and he first journeyed to the Brickyard at age five. Riding 45 minutes on a bus with his father, Nelson, before the sun had risen over the cornfields, Stewart slept in the luggage rack. When the bus got to the track, he was dazzled. "The speed and power...," Stewart recalls. "It took me about a minute to realize I wanted to race there one day."

Stewart, like so many Indiana kids, can tell you the history of Indy by rote. The track was built in 1909 to serve as a testing facility for the automobile industry and given long straightaways and gradual turns to allow the vehicles to achieve and sustain top speeds. The surface was rough -- too rough. In the first week of automobile races, one driver, two riding mechanics and two spectators were killed; jagged rocks could puncture tires and cause drivers to lose control. The track was resurfaced with bricks, which were carried onto the grounds by horse and cart and would remain part of the speedway's surface until 1961, when it was repaved with asphalt over all but a three-foot strip at the start-finish line.

"It's the history that makes Indy so special," says Sam Hornish Jr., a native of Defiance, Ohio. "So many great stories."

The story of Indy, in a lot of ways, mirrors the story of America. For 100 years it has been a bastion of innovation, a place where the best and brightest in motor sports have tested new theories, new concepts. What has been developed at Indianapolis Motor Speedway? Turbo engines, energy-deflecting cockpits, aerodynamic downforce and, perhaps most significant, the SAFER barrier wall, which debuted at the speedway in 2002 and is now a fixture at every major racetrack. In short, the innovation that Indy has fostered has been the driving force behind the evolution of motor sports around the globe.

The Indy 500 has also become a cultural touchstone. To generations of fans it has been America's Roman Colosseum -- with an infield so vast that Vatican City, Yankee Stadium, Churchill Downs, the Rose Bowl, the grounds at Wimbledon and the Colosseum could all fit inside at the same time. Indy is a track where danger and death lurk around every turn; a race where, if he or she has enough guts and guile, even the most unlikely underdog can walk away with the big trophy. Just ask Graham Hill, who in 1966 narrowly avoided a 16-car pileup on the first lap to win. Or ask Hornish Jr., who in 2006 made a dramatic late charge and on the last lap passed Marco Andretti to take the second-closest 500 ever (.0635 of a second). It's also where the greats have flourished, where A.J. Foyt, Al Unser and Rick Mears built and burnished their legacies. All of this is why after 100 years our eyes are still drawn to the Indy 500, truly the Greatest Spectacle in Racing.

Rituals have developed at Indy, from Jim Nabors singing Back Home Again In Indiana before each race, which he first did in 1972, to the winner swigging milk in Victory Lane (thanks to Louis Meyer in the '30s). Indy's timelessness can make race weekend feel like a county fair. "It's not just the traditions that make the 500 the best race," Foyt told me a few years ago. "It's also that once the race starts, you have the best drivers in the planet going at it for 500 miles driving the best cars. As opposed to NASCAR, we can actually pass. On the last Sunday in May there's nowhere else in the world I'd rather be."

Me neither. Because once you head through the tunnel to the infield, you're overcome with one feeling, a feeling that sums up the allure of Indy: Anything is possible.