I'm not sure how this happens

Duv had gotten somewhat miffed at me on the way to Whole Foods last night and I had figured it was because I did not want to hear, yet again, about Star Trek Online or one of his numerous 'interesting' dreams. This morning I find out it was because he said that he had asked that I not turn on the heater for a couple of days so that he could determine the exact problem going on with the car. I had said, yet again, that I did not recall him saying it. He said that yes he had told me, numerous times. to the extent that, he sad, that I had grown tired of discussing it. So why didn't I remember it yesterday? Was I operating on autopilot when I turned it on? Or was it more likely that I had put it out of my mind because I had grown tired of the conversation?