But as the days progressed I had this nagging feeling that something wasn't quite right. The universe is indeed flat. It is simply a matter of perception. For example, consider an image on a piece of paper. Shadows and size give the image a perception of dimensions, but the paper is actually flat and has no depth.
Spiral galaxies appear to be flat when viewed on their edge.
Perhaps when viewed from a great distance, we can see that the universe is flat as a pancake. At this point it really makes no difference whether it is or it isn't, it is our perception that we have to live with. Spread the poison.