On the night before they kicked off their first arena headlining tour to cap off 2006 -- "The Year That Panic! Broke" -- the members of Panic! at the Disco finally realized what a crazy year it's been.

"We all had the chance to sit around last night and kind of look back on everything," bassist Jon Walker said by phone earlier this month from Fort Lauderdale, Fla. "We've been touring so much, we haven't really had any perspective on it. But it's absolutely nuts when you think about it."

Said guitarist and chief songwriter Ryan Ross, "It's been totally insane."

Friends from high school -- and barely out of high school -- Panic! at the Disco played its first concert in August 2005. Its debut CD came a month later. Now the Las Vegas-reared cabaret-punk band's disc, "A Fever You Can't Sweat Out," has sold 1.3 million copies, and its arena shows are filling up.

The biggest factor in its quick ascent was a video for the frantic song "I Write Sins Not Tragedies," featuring pretty-boy singer Brendon Urie in a top hat and ringmaster coat surrounded by a circus freak show. The melodramatic clip won MTV's video of the year award and made them the darlings of teenage rock fans -- especially female ones.

The band also got a leap up on the coattails of Fall Out Boy, whose bassist/bandleader Pete Wentz signed Panic! to his record label and took them on tour.

"Pete helped us get our feet off the ground, you could say," Walker said. "He's been like a mentor and definitely deserves the credit for giving us our lucky break."

Ross and Walker took the time to better explain their overnight-arriving band.

Not only are their videos full of circus rejects, cabaret dancers and mimes, so is their live show. The name of their current outing is the "Nothing Rhymes With Circus" Tour.

Ross: A big part of that definitely comes from us growing up in Las Vegas. I didn't think [the city] had much of an influence on us, but when I got around more and asked people about Cirque du Soleil or "Phantom of the Opera," I realized not everybody can go see those shows like we did.

Walker: We've tried really hard not to be just another band that stands there and plays its songs. We make a point of making a spectacle. But everything that goes on onstage relates to the songs in some way.

Other tracks on the CD include "Lying Is the Most Fun a Girl Can Have Without Taking Her Clothes Off" and -- wait for it -- "There's a Good Reason These Tables Are Numbered Honey, You Just Haven't Thought of It."

Walker: They're not just made-up titles. A lot of them are lines from a movie or a book or whatever. They're part of what sets this band apart so well.

The one snag in the band's quick climb was its split with Brent Wilson this spring, which brought Walker into the band.

Ross: It was tough, because we all went to high school together. It just got to a point where it didn't seem like he was taking it seriously and was along for the ride. And he started to get into things we weren't happy about. It was a hard decision, but with Jon in the band now, we know it was the right decision.

Walker: This band is everything to these guys, so it's not fair to them if someone in the band can't keep up.

Walker is the only member to reach drinking age -- and that happened just two months ago.

Ross: I don't think our age makes a big difference, except maybe we're young and energetic enough to have kept up with our tour schedule this year.

Walker: The great thing about being where we are now at such a young age, I think, is that we all still have so much to look forward to. I mean we all still get to start families and have kids, but we've already accomplished something that a lot of people work their lives to achieve. So we definitely know how lucky we are.