LOUISVILLE, Ky. — For the past half-century, Tom McCarthy watched Kentucky Derby week unfold from the doorstep of his barn and wondered what it would be like to be part of America's greatest horse race. The retired high school biology teacher and principal, whose small stable of modest horses had been based at Churchill Downs since the late 1950s, couldn't imagine he would ever get so lucky.

It took him the better part of a lifetime, but McCarthy finally is experiencing Derby week from the inside. His one-horse, one-man operation is comprised of one very good horse — General Quarters, winner of the Blue Grass Stakes — and one very persistent man. After going two years without training a winner, McCarthy has been the center of attention this week, drawing former students, longtime friends and curious strangers to Barn 37 for a peek at the sentimental favorite of Derby 135.

McCarthy, 75, walked and bathed his rangy gray colt after a Thursday morning workout, then handed buttons bearing his horse's name to the crowds asking him to pose for photos. He obliged every one, knowing this is likely to be his lone chance to live the Derby dream.

"I tell you, it's been fun, it really has," McCarthy said. "I've followed a lot of horses as they've gone to the gate (for the Derby), but I never dreamed I'd be leading one of them.

"It's been a great ride. I don't think this will ever come my way again, so I'm going to have a good time, win or lose."

McCarthy races for love, not for money, and has never had more than a couple of horses in his barn.

McCarthy does everything but ride General Quarters. Thursday, he shampooed the colt after his workout, rinsing the suds from his horse's face before wiping the stray ones from his own. He joked that a week ago, he couldn't even find someone to hold the horse while he bathed him.

A steady ring of 20 to 30 people hovered around the wash rack, offering congratulations and snapping photos of McCarthy and his horse. While he might be a sentimental favorite, McCarthy emphasizes he is not here just for fun. He is proud of the teaching job he's done with General Quarters, and he's eager to see whether the colt is up to the biggest test of both of their lives.

"He's just coming to where I want him," McCarthy said. "I want him kicking the barn doors down on Saturday morning. He's fit. He's ready. And a lot of people want to see him do well."