Lists tell us a lot of things. They tell us which are the best colleges to attend and who are the worst-dressed celebrities. They are good at labeling, but poor at explaining.

Those who pay any attention to movie lists most assuredly know that “Citizen Kane” (1941), which tells the story of a populist crusader who ages into a reactionary hermit, has worn the “greatest film ever made” moniker for as long as anyone can remember.

Having placed first on international critics’ polls for decades, Orson Welles’ directorial debut topped the much-touted “100 greatest movies” list assembled by the American Film Institute in 1998, beating more widely-seen films like “Casablanca” and “The Godfather.”

The question is why. Why is so much praise bestowed upon a movie that unlike the two aforementioned titles, was never a box-office hit, made a poor showing at the Oscars and remained largely forgotten in the years immediately following its release?

For those who are uninitiated, a recently released 2-disc DVD package of “Kane” will go a long way toward making sense of the film’s prized legacy.

The supplemental material, which includes “The Battle Over Citizen Kane,” an acclaimed 1996 documentary that appears on the second disc, illuminates the extraordinary circumstances under which “Kane” was created.

Viewers will learn about Welles, the 24-year-old “boy genius” who was signed by RKO Pictures to the most amazing contract ever offered to a director, one enabling him to take every license and break every convention. The result was a watershed cinematic achievement crammed with visual and sonic innovation.

They’ll also come to know William Randolph Hearst, the newspaper tycoon believed to have been the model for the title character played by Welles, whose boycott against “Kane” is believed to be the primary cause of the film’s box-office failure.

Contributing their insight into these and other “Kane”-related matters are critic Roger Ebert and filmmaker Peter Bogdanovich, each of whom has recorded an audio commentary track on the DVD.

Ebert takes a professorial task, mining each frame of film for meaning. Those already familiar with the movie’s thematic motifs might prefer the track by Bogdanovich, a personal friend of the late Welles whose inside knowledge on the making of “Kane” is unsurpassed.

Unfortunately these features have a shortcoming which plagues almost every discussion about “Citizen Kane.”

We get endless commentary on the merits of Gregg Toland’s deep-focus cinematography, Bernard Herrmann’s musical cues, the use of invisible “wipe” dissolves, the nature of matte drawings and the placement of boom mikes. Meanwhile, the script is treated as an afterthought.

The original screenplay by Welles and Herman J. Menkiewicz, which earned the film’s only Academy Award, remains its most underrated asset. It is as ingenious, funny, tender and shocking as any ever written.

The incidents in the film have a way of seeming at once surprising and inevitable. Again and again the movie attains a shattering emotional pitch, not as a result of melodramatic tricks but because the script lays the groundwork, dropping clues which build to a legitimate payoffs.

One thinks of the moment when young Charles Foster Kane (Buddy Swan) is ripped away from the squalor of his frontier upbringing and placed in the lap of luxury by his benefactor (George Coulouris), never realizing that his happiest days are already behind him.

Still more affecting is the scene in which an elderly Kane, sealed off from humanity behind the walls of his garish castle, destroys his second wife’s bedroom in a teary rage.

With his news empire fading and his political career aborted, her departure from his life comes as the last in a long line of personal losses coinciding with his obsessive accumulation of houses, art objects and other material possessions which end up profiting him nothing.

Since the film is ostensibly the record of a reporter’s encounters with Kane’s friends and associates after his death, these events are shuffled and presented out of chronological order. We see different shades of the man, depending on who is recounting which part of his life.

Just as the reporter (William Alland) comes to the conclusion that no single word can sum up Kane’s life, Welles and Menkiewicz knew that no film could do so either.

Their intent was to provide a series of glimpses into a man’s heart. It starts with his idealism and moves from there to his pride, greed and spite. The movie culminates with still another glimpse, the saddest yet, which hints at a deeper reservoir of feeling which no one in his life was granted access to.

Early in the scriptwriting process, Welles and Menkiewicz gave their film the tentative title of “American.” It fits. In American business, politics and the world created by movies and television, people like Charles Foster Kane are everywhere.

In depicting a man who set out to be a God but failed in the end to be human being, “Citizen Kane” lays bare the dark, hidden side of an iconoclast character central to our national mythology.

Of course, it was American iconoclasm which built some of the world’s tallest cities, led the way for a global communication network and succeeded in sending a man to the moon.

In our journey toward a technological and material Zion, however, we may be losing something more basic and innocent about ourselves.

Above all else, “Citizen Kane” is the greatest film ever made because it inspires us to look inward, to find that something and to cherish it before it disappears.