Being quick with the buzzer is one thing, but it's all for naught without a vast trove of knowledge at the ready.
"It's related to intelligence," Jennings said. "To some degree, I think it's sort of a parlor trick to have all these facts and be able to pull them out at the drop of a hat. It doesn't make you smart in the same way that Stephen Hawking is smart or some guy researching cures for cancer is smart."
Jennings has kept his loss in perspective. "I got beaten by someone very good, that was great," he said. "And it was a relief just to know how the story ended. I've been as much in suspense as everyone else about this whole thing so it was cool to be able to know the end of the story."
But it was also bittersweet. Jennings and Trebek had bonded after four months together, and Trebek told "Nightline" he actually teared up when he said goodbye to Jennings.
"I felt that because, I don't know, it was the end of a wonderful experience for him and for me, I think," he said, adding that the ratings Jennings' run generated helped the show "immensely."
Trebek also said he was happy for the contestant who conquered the champion. "It was quite an accomplishment, the lady defeating someone who had won 74 games in a row," he said. "But there was that element of disappointment also because -- what? You mean Ken lost? Inconceivable!"
So what's next for Jennings? He's taken a leave of absence from work, but says he has no intention of leaving for good. "I love my job. I don't see myself as retiring at 30 just because of this."
He has a book being published next year by Random House "just about my experiences, what in my life led me to this point, what are the bigger questions of trivia and knowledge in our society in general and what that has to do with intelligence, things like that."
Always a master of suspense, don't think he'll be revealing any "Final Jeopardy!"-worthy insights. "I'm not gonna give it away," he said with a laugh. "Buy the book."