Cobb: You're waiting for a train. A train that will take you far away. You know where you hope this train will take you, but you can't be sure. Yet it doesn't matter. Now, tell me why? Mal: Because, we'll be together!
Mal: We'd be together forever. You promised me. Cobb: I know. But we can't. And I'm sorry. Mal: You remember when you asked me to marry you? You said you dreamt that we'd grow old together. Cobb: And we did... I miss you more than I can bear... but we had our time together. And now I have to let go...