Future Ted: You will be shocked, kids, when you discover how easy it is in life to part ways with people forever. That's why when you find someone you wanna keep around, you do something about it.
[present:]
Ted: So I guess good night.
The Mother: Good night. [they kiss] Unless... Do you wanna walk around some more? It's still early.
Ted: Sure.
The Mother: What are you doing?
Ted: Remembering this.
The Mother: Come on.