From childhood, he was a student of Dick Clark, who in the 1950s had pioneered melding music, youth and TV on a show he called "American Bandstand."
"I loved the perception that people came together to hang out and be introduced to new music," Seacrest says. "Dick was brilliant at making everyone feel at home and comfortable, and never getting in the way. That's the key."
That became the key for Seacrest, who, today, is among the most accomplished at doing what he does. But just what does he do?
"At the doctor's office where it says `Occupation,' I always have trouble knowing what to write in that box," he says with a laugh. "I usually put `Host.' I enjoy bringing pop-culture moments and events to an audience, introducing the country to a promising new act or sitting down with an artist who has had a big hit.
"I like being the host of a party. I never feel like I need to be the star of it. Just host."
Seacrest wangled a shift on an Atlanta radio station when he was still in high school. So, from the start, he was live on the air, "and I felt comfortable when things didn't always go as planned. I didn't realize how valuable that would be until later, when I was standing on the `American Idol' stage."
Populated with jittery contestants and volatile judges, "Idol" counts on Seacrest to keep everything on track.
And he does - even when a problem pops up of his own making.
"I remember a results show when we were down to the final two contestants," he says, "and I realized I didn't have the results card with me. I'd gone offstage during a commercial and set it down. So while I'm standing there with those two contestants, I thought to myself, 'How am I gonna leave this shot, get that card and get back, without everybody seeing it?'
"In a split second, I decided the only way was to ask Randy (Jackson) at the judges' panel a question, knowing they would cut to a shot of him - I figured he would give a longer answer than Simon (Cowell) - and I'd have time to jump to the side, grab the card and sprint back."
It worked. No viewer was the wiser.
"Idol" returns January 16, and earlier this month Seacrest was busy as the show completed shooting contestants in Los Angeles, with winners of that round set to move on to the live competition.
At the same time, he tends a growing crop of productions and other business ventures, with some 50 people in his employ.
"I put as many hours into that as I do in all the shows that I'm hosting," he says. "Production is hard work, but fulfilling. That entrepreneurial spirit is a great lesson I learned from Dick," whose dick clark productions established him not just as an entertainment personality, but as a media mogul. "If he wasn't on the air, Dick was in his office working hard."
But does Seacrest ever feel like he's taking on too much?
"Only some mornings," he replies, with a look of mock-weariness. "But then I'll be somewhere watching something and thinking, 'Gosh, I want to be part of that. I feel like I'm missing that party.' I wouldn't want to be home watching New Year's Eve! I want to be bringing it to YOU!"