Previously, Joseph and Evelyn Adama had a son, William. His first wife's name was Caroline, with whom he had two sons, Zak and Lee. The war killed their marriage, and he got furloughed after the war ended, and then he was all alone. Later, his second wife Anne got him back into the Colonial Fleet; he followed up by getting Tigh reinstated later. I don't know what happened to Anne, but Caroline was engaged to be remarried at the time of Galactica's decommissioning, also known as the end of the world. Then Olmos started calling her "Carolanne," creating something of a Crisis On Infinite Ex-Wives which was resolved when they suddenly became one person, even though the timelines don't make sense, because wives get a shitty shake here in S3.5. As long as they're shrieking harridans that abuse their children and/or lovers and husbands, that's good enough. Or...or I guess I can buy Carolanne, no matter the name, because this show is all about recreating your family drama, almost as much as Grey's Anatomy is: Lee's mother was a violent drunk who forgot to apologize and never lived up to her own measure; Kara's mother was a drill sergeant with weird ideas about duty and discipline; Adama leaves infinite wives and lovers behind in pursuit of legal and military ideals. Humanity's a Fleet made up of orphans: all they have are memories of the dead, twisted by time. It's not that you marry a woman just like your mom, it's that you marry a woman who makes you feel the way mom did, for good or ill. Very different proposition, and way more on your side of the line than hers, either of them. Human psychology is based on projection.
Down on New Caprica, during a party to celebrate the breaking of ground, President Gaius's memorable imprint on yet another world, Laura Roslin stood in the alluvial deposits of a virgin planet and tried to illustrate for her closest friend what a new world would be like: a world without war and fear and pain, a future that wasn't always rushing toward you, but waiting somewhere on the horizon for you just to walk toward it. I don't know if Bill heard what she was saying, but this was what she was saying: "In the mountains north of here there's this little stream. The water is so clear, it's like looking through glass. I am thinking of building a cabin." She never did. He never got to wash the alluvial deposits off his feet; he never even saw the stream.
Later, on the run again, Chief Galen Tyrol admitted to Lee that he was having trouble with his wife -- their family, for which Bill Adama still feels responsible, started on New Caprica. In some ways it ended there, I guess. They had to start over, and they still hadn't. "Marriages: Why we build bars," Chief said. And Laura lay back on William's bed with her shoes off, and touched his arm tenderly, and discussed matters of political and national importance, and of the most personal importance: how we go on. How we knock the alluvial deposits off our shoes and forget the disappointments and the triumphs of that cursed world, and remember again how we used to do things. How to go back to simply running, after the awful chance to rest.
Now: Bill's younger, in the backyard of a beautiful house on proud Old Caprica; none of that yellow irradiated glow, just wind chimes and birds and a billion birds. He looks out the window, peaceful and strong.