A knife allegedly found buried at O.J. Simpson's former home stayed hidden in a retired police officer's possession for years. Police are now testing it for evidence in the 1994 murders of Nicole Brown-Simpson and Ron Goldman. (Gillian Brockell/The Washington Post)

Greetings, young readers. Perhaps you’re wondering why the old people you know are chattering so much about some 20-year-old murder trial, blathering on even more than they usually do about things that happened in the olden days. Friday, the chatter was especially loud, with the LAPD confirming that they are investigating a knife that had been allegedly found on O.J. Simpson’s former property.

There’s a good reason for all the hullabaloo: Everything about the Simpson trial was a level of nutzo crazy this country rarely had seen before and probably has not seen since. But why?

Let’s start at the beginning with O.J. Simpson, who first came to fame as a running back at USC in the late 1960s. He won the Heisman Trophy in 1968 after rushing for 1,709 yards and 22 touchdowns and was drafted that year by the Buffalo Bills. After a few rough years on some bad Bills teams, Simpson in 1973 became the first NFL running back to rush for 2,000 yards, setting a single-season record that stood for 11 years. Three more Pro Bowl seasons followed — Simpson set the NFL’s single-game record with 273 rushing yards against the Detroit Lions in 1976 — before his body began to break down. After two desultory seasons with the San Francisco 49ers, Simpson retired after the 1979 season as the NFL’s No. 2 rusher of all-time.

By then, he was famous. Obviously nicknamed “Juice,” the telegenic, charismatic Simpson began taking on commercial and film roles even before his career ended. His commercials for Hertz rental cars were particularly memorable, back in the days when everyone had to actually watch the commercials and not skip over them with their DVRs.

Simpson continued on this path in the 1980s, his fame growing exponentially. He was a color commentator for ABC’s “Monday Night Football” from 1983 to 1985 — in an era when those games drew eye-popping TV numbers and not merely the pretty good TV numbers they draw today — and later helped call games for NBC. He also appeared as Nordberg in the popular “Naked Gun” comedies. These movies hold up well and you should watch them, especially the first and third ones.

In 1985, Simpson married a woman he had met years earlier — when he was still married to his first wife — named Nicole Brown. They had two children together, but soon the marriage took a bad turn. Simpson pleaded no contest to a domestic violence charge after an incident on Jan. 1, 1989. Here’s the New York Times:

According to police records released Thursday, Mr. Simpson beat his wife, Nicole, so badly on Jan. 1, 1989, that she required treatment at a hospital. The records also portray her as terrified for her life.

When the police arrived at the couple’s house after the beating, the records show, Mrs. Simpson ran out of the bushes, yelling: “He’s going to kill me! He’s going to kill me!” She told the police that they had been called to her house on eight other occasions after her husband had beaten her, the records say, and Mr. Simpson complained about the frequency of the police calls.

Simpson was sentenced to 120 hours of community service and two years’ probation, and he and his wife divorced in 1992.

All of this setup is to show that O.J. Simpson was really, really famous by the time June 1994 rolled around. Not viral famous like today, when renown comes and goes like a passing cloud; the Internet as we know it was still in its infancy, most people didn’t even have email accounts and cellphones barely fit in your backpack, much less your pocket. No, O.J. Simpson was famous famous. Your-mom-knew-who-he-was famous. Your-grandma-knew-who-he-was famous.

And on June 12, 1994, Nicole Brown Simpson and Ron Goldman, an innocent bystander who was returning eyeglasses left at a restaurant, were brutally killed outside of Brown Simpson’s condo building in the tony Los Angeles enclave of Brentwood, where O.J. Simpson also had a nearby estate. Both were stabbed multiple times, and Brown Simpson was nearly decapitated.

Police zeroed in on O.J. Simpson almost immediately and, four days later, he agreed to turn himself in. But when the appointed time came for his surrender, Simpson was nowhere to be found. What followed launched one of the more bizarre stories in recent U.S. history, with television and celebrity and law enforcement and the ingrained, freeway-choked weirdness of Los Angeles coming together to form a Frankenstein monster of a story.

Simpson had absconded with Al Cowlings, a former teammate, in his white Ford Bronco. No one knew where he was. Robert Kardashian, Simpson’s longtime friend and, yes, the father and ex-husband of those people with the same last name, read a letter from Simpson in which he proclaimed his innocence and seemed to suggest he was about to kill himself. And for the first time in television history, a famous person’s suicide note was read live over the air to millions of people across the country.

Then, about 90 minutes later, Simpson’s white Ford Bronco was spotted in Orange County, and thus began a slow-speed chase that left television viewers rapt and Southern Californians cheering alongside the highways and helicopters blacking out the sky. It was such a spectacle that NBC made the decision to bump Game 5 of the NBA Finals — not just the playoffs, but the Finals — to a tiny corner of the screen in favor of the chase.

Simpson eventually returned to his home and surrendered. We moved on to the “Trial of the Century.” Things got weirder.

In this corner, the prosecution: deputy district attorneys Marcia Clark and Christopher Darden. In the other corner, the defense, a “dream team” of legal minds who came to Simpson’s side mainly because he could afford it: Robert Shapiro, F. Lee Bailey, Alan Dershowitz and Johnnie Cochran, who in most ways became the face of the trial. Overseeing it all: Judge Lance Ito.

All of these people became — at least for a year or two — household names, more famous than you or I or anyone you know will ever be. So did Kato Kaelin, a bit-part actor whose sole claim to fame was that he was living in O.J. Simpson’s guest house at the time of the slayings.

The country’s burgeoning cable networks — most households got somewhere between 36 and 70 channels, which seemed like a lot back then — had hours of programming to fill, and they got it, mainly because of Cochran’s legal showmanship and the fact that the prosecution was somehow losing even though nearly all of the evidence pointed to Simpson’s guilt. America was introduced to DNA evidence, which is now the basis for pretty much every other scripted drama on CBS, and the DNA all but confirmed Simpson was at the scene of the crime. The defense nevertheless cast doubt on it. There was a bloody glove, bloody socks, blood on the Bronco. Most of it was found by an LAPD detective named Mark Furhman. The defense painted him successfully as a racist who may or may not have planted the evidence to convict a famous black athlete and celebrity.

And then the finishing move: the defense had Simpson try on the gloves in court. They didn’t seem to fit:

“If it doesn’t fit, you must acquit” became a catchphrase:

Finally, on Oct. 3, 1995, the jury had reached its verdict, and America stopped what it was doing and found a television.

Eventually, it all died down. Simpson made promises to “find the killers,” while also seeking out tee times and avoiding his creditors. The victims’ families sued him for wrongful death in civil court and won, earning $33.5 million in damages that mostly weren’t paid and trying their best to remind everyone that this whole thing revolved around two people who were murdered. Simpson wound up broke and eventually embroiled himself in a plot to steal back some memorabilia he believed was his. Barging his way into a Las Vegas hotel room with a gun, he was soon arrested and convicted on kidnapping and armed robbery charges. Now 68, he sits in a Nevada jail on a 33-year sentence, though he’s up for parole next year.

But now it’s all coming back to us in a bizarrely coincidental 1-2 punch, with FX airing “The People vs. O.J. Simpson” to critical acclaim and Friday’s news that a knife had apparently been found at some point while they were tearing down Simpson’s old estate in Brentwood. Who knows if anything will come of that, but if anything, it’s a reminder of a quainter time when a viral story reached epidemic proportions.