The lesson is when your girlfriend says "Your closet needs updading" give up immediately and go to the mall with her because she will win.

You don't want to hold out for the flattery and the promise of drinks afterwards? Negotiation is an important skill.

And what is the point of negotiating if you know there is just no way you will one this one :)

Knowing what you're going to commit doesn't tell you anything about what the other negotiator is willing to commit.

Good lesson.