Patricia Felt had stood in front of the Vietnam Veterans Memorial many times before, but one day last week she saw something she had never noticed: Her last name engraved in the glossy black granite.

She consulted the catalogue with the list of the war's casualties and saw that all the information -- the date of death, the home town -- looked exactly right. It caught her off guard; she had never thought to look for anyone she actually knew.

"I think that must be uncle Joe's son," she said. "I've got to call my sister and tell her about this."

A few yards away, Ralph Funk was viewing the memorial for the first time. "Larry, old boy," he said, eyeing the name of his nephew, "I finally got to see you." Before he could finish that sentence, emotion took the 57-year-old veteran by the throat, squeezing the last two words to a higher pitch.

The two experiences -- a new discovery, a first encounter -- were repeated many times during the day, as they have almost every day for the past 20 years. Felt, of Alexandria, and Funk, of Western Maryland, are among more than 40 million people who have made the Wall the most popular memorial in America.

Since its dedication 20 years ago this week, it has been celebrated and imitated, analyzed and criticized, amended and altered. And, as Felt and Funk discovered, the Wall that lists the names of 58,229 casualties has not lost its ability to surprise.

"I think of all the people I knew in the war," said Susan Hendrickson, an Oregonian visiting for the first time, slipping past Funk to scan more names. "I wonder where their names are on this wall. Just look at all these. . ."

Many Voids to Fill Jan Scruggs shepherded the memorial from an abstract idea to the mass of stone that stands today. After a tour in Vietnam, Scruggs studied sociology and collective psychology at American University. He still studies those subjects today, though not in a classroom.

"This book," Scruggs says, grabbing "Carried to the Wall" by Kristin Ann Hass, a sociologist at the University of Michigan, "traces fundamental changes in how the public mourns to the Vietnam Veterans Memorial. There are many examples of things the Memorial influenced, like the AIDS quilt, and a lot of other similar memorials across the country. There's a theory that highway headstones -- the crosses and markers people leave at the scene of accidents -- can be traced back to the Vietnam Veterans Memorial."

The memorial itself, he says, can be traced to 1979, when he watched "The Deer Hunter," a movie chronicling the dark struggles of returning Vietnam veterans. When Scruggs took his eyes away from the screen, he saw a void unfilled by ticker tape, molded clay or cast bronze. The shape of this void, he figured, was monolithic. An obelisk maybe. Something tall and proud, like every other memorial he'd ever seen.

So Scruggs founded the Vietnam Veterans Memorial Fund to raise money for a memorial. He still runs it, working in a downtown Washington office with a staff of eight. The organization raises money for the Wall's upkeep and has launched an educational program for teachers. It also takes calls from imitators, and the calls keep coming.

"A problem is starting to surface," Scruggs says. "I just got a call from a guy in San Diego who said, 'Wouldn't it be cool if we had an exact, full-scale replica in San Diego?' . . . This thing begat memorials in all 50 states."

The memorial fund has no copyright on the design of the Wall, which Scruggs says might have been a mistake. But he understands why people who visit want to replicate their experience at home: It's a sociological phenomenon that has to do with collective grieving, healing and the filling of voids. He just had no idea so many voids would prove to be the same shape.

'A Quiet Place' The design of the memorial is 21 years old, the age of its designer when she illustrated her idea on a plate for fellow students in a Yale cafeteria in early 1981.

Maya Ying Lin, an Ohio undergraduate, was studying funereal architecture when her professor assigned the students to enter a nationwide design contest for a Vietnam Veterans Memorial. A panel of judges sifted through 1,421 anonymous entries and picked number 1,026.

Lin's entry included sketches of her vision: polished black granite dug into the earth, stretching in an obtusely angled V. The entry also included an essay, handwritten on a single page. It said the walls would emerge from the earth, the granite would reflect light and the lettering would be simple.

"It is up to each individual to resolve or come to terms with this loss," she had written. "For death is, in the end, a personal and private matter, and the area contained with this memorial is a quiet place, meant for personal reflection and private reckoning."

Lin's design loosed a flood of scorn and complaint: The V was a subversive symbol of the peace movement, meant to undermine the sacrifice of veterans. Black was derided for being the color of shame and degradation. The design was unheroic, too abstract, a poor attempt to be avant-garde and, as author Tom Wolfe wrote, "a tribute to Jane Fonda."

Lin's response: The memorial was black because white south-facing stone would blind its viewers in sunlight. It was shaped in a V to point toward the Washington Monument to the east and to the Lincoln Memorial to the west, placing the memorial in an historical context. The design was purposefully simple because embellishment upon something so moving would only diminish its effect.

For more than a decade after her experience with the Wall, she declined to talk publicly about her Washington experience. She now speaks occasionally, has published a book about her work called "Boundaries," but doesn't go out of her way to court publicity. Calls and faxes to her New York studio last week were not returned.

According to an employee there, she plans to attend anniversary ceremonies on Veterans Day, Nov. 11. Organizers list her as a speaker.

"I like to think of my work as creating a private conversation with each person," Lin wrote in her book, "no matter how public each work is and no matter how many people are present."

'I Saw Myself' Forrest Brandt's voice falters when he talks about his first impressions of the Wall. He takes extra care with his phrasings, full of long pauses and false starts. Then he just lets it fly: "I guess I was still harboring some resentment. I would hate to admit a racist thought, but I was like, 'Why an Oriental to design the Vietnam memorial? Isn't there a quote-unquote American out there who could do it?' And the design itself just sounded wrong. 'What do you mean, a ditch? There's nothing heroic there, just a list of dead names.' "

Brandt surprised himself and his friends in 1982 by sobbing at an unsolicited memory of his 10 months in Vietnam. He decided it would probably be healthier to confront the past, not suppress it. He joined a veterans group near his Cincinnati home.

By chance, his involvement coincided with national debate of the design of the memorial. He sided with the opposition. When his group decided to visit the Wall that autumn, Brandt refused to go.

"I expected them to come back and say, 'Oh, it was awful! A disgrace!' Instead they came back overwhelmed. To a man, they said it was a stroke of genius."

Though some of the original detractors still say they believe the memorial's design is unremarkable, many dropped the decibel level when they witnessed the effect it had on veterans. Tom Carhart, a decorated veteran who found himself at the forefront of public opposition, calling Lin's design a "black gash of shame," now says: "I took a stand; I was wrong. I was apparently proved wrong by the American people. It happens."

Brandt came to the same conclusion when he visited the memorial for the first time in 1984. He has revisited it and plans to attend the anniversary ceremonies this week.

"I looked at the names and I saw something more," says Brandt, a middle school teacher. "There's a reflection you see, which is the genius of Maya Ying Lin's idea. I saw that I was part of those names. I saw myself in there."

Ever Evolving Arnold Goldstein supervises Washington's monuments and memorials for the National Parks Service, the agency responsible for day-to-day maintenance of the Wall. He began overseeing the memorial less than a year after it was dedicated, and has seen the Wall -- and consequently the Mall itself -- evolve without pause.

"There's constant wear, constant use," says Goldstein. "You can clean it up, then another busload of people comes through and it looks like you were never there. But actually we have very few problems with it because people seem to have a lot of respect for it."

But the glossy surface needs regular cleanings. It's one of the most interactive memorials in the country: Every day, people rub the engraved letters with a pencil over paper, taking home a keepsake but leaving palm prints and worse. Last year, about 3.75 million people visited the memorial, and about 2.13 million visited this January through July. It is usually the top attraction of all the monuments in the city, Goldstein says.

That popularity has spawned a spate of memorials that is continuing to change the landscape of the Mall, to the chagrin of some and the delight of others. After the Vietnam Veterans Memorial, a Korean War Memorial soon followed. The Iwo Jima statue no longer seemed a sufficient marker for World War II, so a large memorial to that war is being constructed on the Mall. As Scruggs says: "We sort of created a need for recognition, and I think that's great."

The monument itself has changed. In 1983, the walkway in front of the memorial was added, along with extensive landscaping. A year later, a statue of three servicemen and a flagpole were unveiled nearby, and lights were added for nighttime viewing. The 1990s brought a Vietnam Women's Memorial, widened walkways and the importation of extra granite in case panels need replacement. Current projects include an electronic reference system to help visitors find the location of names faster than they can in the books.

"There are always things to do," says Goldstein. "There always will be."

Etched in Memory On June 30, 1968, a firefight left Army Pfc. Paul Zylko without a right arm, right eye and left thumb. He suffered serious burns. His face was forever disfigured.

When he got back to New Jersey, Zylko tried to live a normal life. He raised a family and built a career working with those suffering from cerebral palsy. But Zylko couldn't forget, nor did he try. He visited the Wall several times.

During one visit, he and another wounded veteran were walking in front of the Wall, reading the names of friends, when they heard applause coming from bystanders. It was for them.

"The Wall was very special to him," his wife, Kathleen Zylko, said. "He really, really liked it."

After the firefight, Zylko needed blood, and a transfusion left him with hepatitis C. He died Sept. 8, 1999, after a long battle with the disease.

In spring, his name was engraved on panel 54W, line 24. It is one of 290 added since 1982.

Kathleen Zylko said that when she saw her husband's name etched in the granite -- a little brighter than those around it -- only then was she able to fully come to terms with his death. Like millions of others before her, she found comfort in seeing and touching his name.

"It was very special to me, and it would have been very special to him," she said. "It makes sure my husband will never be forgotten. Just like all those other names."

Jessica Felt of Alexandria reaches to touch an engraved name of a soldier she and her sister Patricia believe to be a relative.Rain soaks the statue of three servicemen at the Wall, which was added two years after the memorial opened. The Wall has undergone constant change in its 20 years.Jan Scruggs, a Vietnam veteran who founded the Vietnam Veterans Memorial Fund, reads a letter left by a loved one at the base of the Wall.