A space traveler discovers an almost identical replica of their childhood city on an alien planet.
The key feature of this alien planet is mixture of different levels of what on Earth we refer as "realism." Some objects are very detailed and more unique, and others are like low polygon 3D models, and more generic. Apparently everything we see on this planet is generated by a very advanced AI, but it does not have enough time or patience to render everything perfectly. As a result, the objects, signs and templates exist next to each other. But everything is equally degraded and decayed, because it is all located outside and nobody paid attention to this for decades.
According to space mission reports, the planet can simulate perfectly visitors’ childhood memories. They say: it looks exactly like the places where we grew up, etc. But when we show them the actual photos of their childhood, they realize that the planet is totally utterly alien. It only simulates their memories, inducing this effect of mis-recognition.