Disclaimer: I own absolutely nothing even remotely related to Battlestar Galactica; it all belongs to Ron Moore and David Eicks (and the other people). Trust me, if I owned it, there'd be more focus on different characters.
You wonder sometimes why you care so much. Why it all matters to you. When this – this thing – became so overwhelming important, that it ate at every thing you did, everything you were. You can't remember the last time you saw something, did something, said something, heard something, that didn't come back to this. You remember when you used to be strong, when you used to be able to brush off everything and do your job. Your job. You laugh quietly to yourself, because you know that it was never just your job. But now, it's more than even that. Being the job means you don't think about the pain, the sorrow, the hurt that has become your life. You realize you just said three words that mean the same thing, but somehow they are three very different pieces to one frakking horrible puzzle.
You look at him, and you say those three little words one last time. "I'm leaving you." You say it with conviction and you know it's the right decision. You've known it since you had to go get Starbuck off that miserable excuse for a planet, and you know it now. He looks at you, but you can tell he's not seeing you. So you pack up the rest of your things, and you move back into your old quarters, before you were married, before you were an Adama. And no one says anything. No one asks how you are, or tells you they knew it was coming, or jokes about how you won or lost them money. They just act as if you never left, you never changed your last name, you never lived on Pegasus as an XO. And you realize that you want them to notice. You want someone to say something, to regard you as something other than insignificant.
And, for a moment (just a split second) you wish Billy were still alive. Because you know that Billy would've never forgotten about you, that he would've made you feel as though you were the most important person in the universe. But you suppress that, you bury it down deep, down where you have your guilt over abandoning your people, where you mourn the last conversation you had with your father, down where it can never erupt, never get out. Because dealing with all that emotion would make it impossible to do your job.
And, really, what else do you have left?