Disclaimer: I don't own these characters, they belong to Shonda & co.

Selective Amnesia

"I'm done, Derek."

Three months after moving into his trailer, Addison couldn't take it anymore. She was done. The gossip at the hospital, the resentful interns, the vacant stares after – and sometimes during – sex, the guilt that didn't go away, the broken promise of ending things with Grey, and the sad excuse for a marriage. It was too much. It wasn't worth it anymore. And now, she had to add to the mix a dog that – cute as he was – symbolized her husband's feelings for Meredith Grey, in some twisted way. She often told herself she was seeing things that weren't there. That, sometimes, dogs were just dogs and not furry four-legged metaphors. But the truth was, she couldn't help it.

In a life that was filled with individual possessions, the dog stuck out like a sore thumb. Derek's trailer, Addison's shoes, his land, her car, his neurosurgery department, her neonatal department… and Derek and Meredith's dog. Their dog. Maybe she was seeing metaphors everywhere, but she couldn't ignore them. Not when they chewed her shoes and slobbered all over her face when it was time to wake up. The one thing she liked about Derek's trailer, and she felt as if she was borrowing it from Meredith. Actually, all her life felt like a loan. She had Meredith's McDreamy, and her dog, and – she figured – her dream life. And she was done.

"What do you mean, you're done?"

He asked it in that way of his, the one that was between curious and confused, and she wondered if he really didn't think there was a problem between them. If he wasn't aware of the fact that they were both miserable together. "I mean I'm done. This isn't working. This is hardly a marriage. You're obviously not interested in working for this, and I don't want to work for it anymore. I'm done." His face was expressionless as he listened, and she got up from the bed and grabbed the suitcase she'd packed while waiting for him to get home. She knew he'd try to stop her even before he spoke.

"But I am. Working on it."

She sighed as she turned around to look at him. For once, she wished he wouldn't try to do the right thing. "Derek…" But he cut her off. "No. Listen to me. I'm trying. I'm trying to forget about Mark, and I'm trying to forget about Meredith. It's not easy, but I'm trying." Addison looked at him for a moment, in silence. Trying to read him. Trying to figure out if he really wanted her to stay or he just didn't want to be the one who didn't try. The one who didn't really do the right thing. "That's not what I want, Derek." He looked definitely confused then, and she couldn't blame him. "I don't want to forget what happened with Mark, and I don't want to forget what happened with Meredith."

"But I thought you…" Addison didn't let him finish. She needed to say exactly what was on her mind, for once. "I want us to remember what happened, and learn from it. I want us to remember Mark and Meredith and why everything happened. I want to remember the good times and the bad times. Remember what we had and why we lost it. There's no such thing as selective amnesia, Derek, and we can't have the good memories without the bad ones."

He stayed silent after she finished talking. And she knew it was over. She knew he wouldn't be able to work on their marriage, to sleep next to her and stay married to her if he couldn't pretend Mark and Meredith had never happened. And, once again, she couldn't blame him. It was too much, even for them. Even for Derek and Addison. And she grabbed her bags once again and walked out of the trailer, knowing shed never come back.

"Goodbye, Derek."

One week later, Addison opened the door of her hotel room to find Derek standing on the other side. She'd been avoiding him for seven days. It was time to sign the divorce papers that had been resting in the second drawer of his bedside table for months. She wished they didn't have to, but she knew there was no other way. They had waited long enough.

Derek didn't sit down when he walked inside, and she decided it was too late for politeness and sat on her bed, waiting for him to talk. He waited in silence for a few moments, and she wondered if it was as hard for him as it was for her. Maybe it was. Maybe getting a divorce wasn't easy for anyone, intern romance or not. "I'm sorry I was absent." And Addison looked at him, half confused and half interested. Maybe this was one of those situations where you're supposed to put it all in the open and get your clean conscience back. Sort of like a deathbed.

"I'm sorry I stopped seeing you. I shouldn't have taken you for granted. I'm sorry I didn't really end things with Meredith, and I'm sorry I never really tried to make things work. I'm sorry I hurt you." Addison nodded softly. "Okay." It was all she could say. She still didn't know exactly what she had to say or do while her soon-to-be ex-husband apologized to her. But Derek kept talking, and she figured it wasn't her turn to speak just yet. "I'm sorry I can't stop thinking about you cheating on me with Mark. I wish I could. I resent you for that. I'm sorry I hate that you ruined my relationship with Meredith. I'm sorry you hurt me." She looked down at that. He had every right to hate her, like she'd hated him before. They both had reasons to hate each other.

"I wish I could forget it all."

And she nodded again. Sometimes, she wished so, too. "But, if it's all or nothing, if selective amnesia is not an option… I'll keep it all." He sat down then, and kept talking. "I don't want to forget the first time I fell in love. I don't want to forget med school, or my residency, or my first solo surgery. I don't want to forget the patients I've saved or the surgeries I've performed. I don't want to forget my first apartment, my wedding day or my first house in Manhattan." Addison could feel the tears threatening to fall, and she wished he'd stop talking and leave. She didn't want to cry in front of him. "You are part of all those memories. You were there, with me."

"I don't know if you're the love of my life." She rolled her eyes, because he was good at torturing her. She almost wished he'd just thrown the signed papers at her instead of giving her one last speech. "But I've tried to forget all about you. I've tried, but I can't. I don't want to. You made those memories with me. You made them better. So I want to remember it all. And the bad times, the times you made it worse, or I made it worse for you. I want to learn from the bad memories, and try to build new good ones together. If you still want to fight." She looked at him then, trying to figure out what to say.

He was smiling at her. With that smile of his that was both encouraging and charming. The one that convinced her to go out with him all those years ago. She knew she should have doubts. She should have been thinking about the other broken promises, and the other times he swore he was fighting too. But she wasn't thinking about that. She couldn't. She trusted him – against her better judgment – and there was nothing she could do about it. And, since she couldn't think of anything to say, she kissed him instead, and she smiled against his lips when he kissed her back. It was familiar in a way it hadn't been in years. They were kissing without thinking about anyone else. Without accusations and resentment in the background. Just kissing. And she'd almost forgotten how perfect it felt.

Later that night, Derek held her close to him as they laid in bed, trying to catch their breaths. She didn't thank him, and she didn't tell him it'd been amazing, because the content smile on his face told her he already knew. With his fingertips drawing lazy circles on her stomach and his legs tangled with hers, Derek dropped a kiss on her left shoulder before leaning forward to whisper in her ear. "Happy twelfth anniversary, Addie." And she smiled and turned around in his arms to look at him. "You remembered." Derek shot her the playful smile she hadn't seen in years and did an almost perfect impersonation of his wife when he replied.

"There's no such thing as selective amnesia, honey."