My girlfriend is at the airport. I am at home. Collecting her would require forty minutes of driving, and I have decided that this is a poor use of my evening.
Her principal objection is that we have been together for three years. She has also mentioned the time she collected me after dental surgery and several other occasions on which she incurred costs for my benefit. I do not dispute the history. I dispute its relevance to the decision currently available to me.
Those hours cannot be recovered. Driving to Terminal B will not return her Tuesday afternoon in March, any more than buying additional shares in a failing company recovers the original investment. A relationship can contain a great deal of past generosity without every subsequent request becoming a profitable opportunity to add more.
The appropriate comparison is between the future in which I go and the future in which she takes a taxi. In both, she arrives at our apartment. In the second, I retain forty minutes and she incurs a fare. There may be additional benefits to my personal attendance, but “after everything I've done for you” is not an estimate of them.
It is true that I agreed to collect her. Commitments can improve coordination, and she apparently relied on this one when deciding not to book a car. But the booking window has now passed. Keeping my promise cannot restore her earlier alternatives; it can only impose an additional cost on me. We should be evaluating whether that cost is justified from this point forward.
The strongest objection concerns future trust. If I fail to appear, she may become less willing to rely on me. That belongs in the calculation. However, its magnitude depends on what she learns. Updating from “he declined an inefficient airport trip” to “he does not care about me” would be an extremely broad inference from a narrow observation. I am reluctant to subsidize that inference by driving.
She has since said that she is reconsidering the relationship. This changes my estimate of its continuation value. A partner who makes three years of shared life conditional on forty minutes of driving is attaching a remarkably high price to a small transport benefit. The threatened loss therefore provides some evidence that I was overvaluing our future cooperation.
I understand that she sees the same history as a reason to come. I see it as something that remains true whether or not I start the car. If the prospective case for collecting her were strong, it would not require repeated appeals to an investment neither of us can recover.