Large dark triangle shaped completely silent hovering almost directly overhead.

I'll try to shorten this with key details, but it's probably going to be quite long. Before I describe this sighting let me start with what I consider to be a very strange fact. The date I provided is an estimate. It could be off by a year or so and the month is based of memory of the weather and temperature. At least a full decade passed when out of the blue around late October of 2001, as if I regained access to a repressed memory, I could recall this event as if it happened that day. Prior to this I have no recollection of this event and at no point was this sighting discussed. After returning home with a few grocery bags in tote, as I'm preparing to open the front door to our house, my mother and I found ourselves gazing up at the sky. As I recall she was the first to notice what I remember as a perfect black triangle. The sky was clear and living in a rural area with very little light pollution, it took a few seconds to make out the outline of the object. With absence of stars it at first appeared to be a triangular hole in the sky. Soon I could make see the edges of the craft or object. The three corners came to a sharp point and it was equal on all sides. There were no lights on the craft (assuming it's a craft), and it puzzled me how it made absolutely no sound. I recall her seeming somewhat disinterested. In the time it took to take the groceries in and return outside the object had vanished. I cannot say for sure, but have felt like there may have been missing time. I have never discussed this with her and cannot explain why. I have told this to a few people with no issues, but for some reason we have grown very distant and I have never mentioned this to her. A few times years ago after phone conversations with my mom I would feel disappointed that I forgot to ask her if she remembers this. Instead of calling her I would just tell myself next time.