It was an evening in early April, and Conan, Liza, their two children, Beckett and Neve, and the golden retriever, Bosco, were having dinner at home. Knowing that they would be moving in 2009, they bought a brand-new house in West Los Angeles more than a year ago. The many huge rooms, most of which have double-height ceilings, are sparsely furnished with overstuffed sofas and chairs. The walk-in closets are so spacious that Conan has an elliptical trainer in his and Liza has a desk in hers. Naturally, there's a pool in the backyard, and I lost count at four guest rooms and three dens. "I have moments of 'Whose life is this?'" O'Brien said as he gave me a tour. "I get up in this house, I get in my car and I drive to work, and it's like I've adopted a new personality."