For a contingent of Americans born between 1970 and 1992, Monday nights are going to be a childhood fantasy fulfilled. Starting at midnight, Nickelodeon is digging into the archives and airing four classic shows in a block of neatly packaged programming: “The ’90s Are All That.”

Go ahead and watch a promo, the one with Kenan Thompson sitting on that bright orange sofa. Yes, he is on the Snick couch. The sitcom “Kenan and Kel” will air alongside sketch comedy show “All That,” “Clarissa Explains It All,” Nick’s first live-action comedy, and the animated series “Doug,” four of Nickelodeon’s most iconic shows from the 1990s. Obsessives can also sign on to 90sAreAllThat.com to connect with other fans, access exclusive content and lobby for beloved shows they want to see on air.

The block began to take shape last summer, when a bunch of young Nickelodeon interns did a presentation for Nick executives in which they said: “bringing back classic Nickelodeon is a real digital opportunity.”

“When the numbers went from 9 million Facebook fans to 15 million fans, we said, ‘This is more than a digital opportunity. This is a TV opportunity,’ ” said Cyma Zarghami, president of Nickelodeon, citing the multiple sites viewers created demanding the return of these old shows. “We’re hoping to make it very interactive. Part of the goal is letting people tell us what they want.”

Nickelodeon started out as the kind of weird, wacky channel kids would have dreamed up for themselves, right down to the orange SPLAT of a logo. Kids don’t want squeaky clean. Kids want to be slimed. Kids want pies to the face. Kids want to see other kids being kids. And Nickelodeon was the place that provided it.

“Nick was the first and only branded network for kids,” said Zarghami. “One of the reasons I think people remember Nick fondly is that we housed all the stuff they loved. Our original mission was to lead people to believe that Nickelodeon was run by kids, and that if you walked down the halls of Nickelodeon, you would see kids who looked just like you playing there.”

Brian Robbins was the writer and creator of “All That,” a Saturday Night Live-style show that launched the careers of Thompson, Amanda Bynes and Nick Cannon. “There was really nothing like it on television,” said Robbins. “The show had a really urban, pop flavor. Everything up to that point was very soft, nice and sweet — very cookie-cutter. This was a very irreverent show.

But those kids who spent Saturday nights watching Snick are in their 20s and 30s now; isn’t it time to put away childish things? What is a devoted “Friday Night Lights” fan going to get out of “Double Dare”? What themes left unexplored by “Mad Men” are explained in total by Clarissa?

It is exactly because these fans are “too old” for these shows that this programming is so popular. This is television that’s not really about television. Turn on TeenNick and you get to do the time warp back to a carefree childhood.

Shawn Robare, a 34-year-old from Atlanta launched his site, Brandedinthe80s.com, in 2000, when he was in his early 20s. The site revisits all the pop culture from Robare’s childhood: the songs, the comics, the television shows.

“I had just married my wife. I was giving up a lot of stuff about being a teenager,” Robare said. “As soon as I started having those responsibilities, I wanted to become a kid again.”

What people know anecdotally to be true of nostalgia is, in fact, backed by science.

A study done by Jason Leboe, an associate professor of psychology at the University of Manitoba in Winnipeg, Canada, suggests that the act of remembering alone makes people happy, even if the memory is bad. Recalling something — say, the lyrics to the Camp Anawanna alma mater — makes you feel good, even if you didn’t like “Salute Your Shorts.” That’s why one-upping friends with arcane Nickelodeon trivia is so much fun: The act of remembering is an end unto itself.

Anyone with a television set is familiar with the pleasant feeling that stems from rewatching the shows you grew up on: From “I Love Lucy” to “The Andy Griffith Show” to “Happy Days” to “The Golden Girls,” syndicated series are the televised equivalent of comfort food.

The Internet has allowed people to engage in reminiscing on an unprecedented scale. It’s easier than ever to dig up the past and communicate with people who share the same memories.

“The Internet is perfect for nostalgia,” said Taylor Trask, whose site, IMiss90sNick.com, aggregates videos of ’90s Nickelodeon shows.

Trask is only halfway pleased with Nickelodeon’s foray into retro programming. “I would love if they would do some online streaming component,” he said. “They could be making money on these things with ad revenue and Amazon and iTunes.

“They’re putting their toe in the water, which is a good start. I wish they’d do more. … You can tell they’re kind of scared. Like, it’s on from 12 a.m. to 4 a.m. so if nobody watches, it’s fine.”

The appeal of this block, Trask said, is obvious. In an increasingly fragmented society, people crave a communal experience. “We watched it together before, let’s watch it together again.”