Children speak from somewhere unfiltered
For the first few years of life, children haven't yet absorbed the social rules about what is fine to say out loud and what isn't. That makes their observations sometimes uncomfortably sharp — because the filter you and I take for granted just isn't there yet. A four-year-old will look at a stranger's face, name what they see, and walk on.
What strikes adults as creepy is often the cleanest, most literal version of what we ourselves are quietly thinking.
Pattern, mystery, projection
Children have a developing theory of mind, an active imagination, and a vocabulary that is still small enough that they reach for archetypes before they reach for nuance. The result: they describe the world in the same shapes our oldest stories use — death, sleep, the watcher in the corner, the friend nobody else can see.
We hear those shapes and feel a small chill. That chill isn't evidence of anything supernatural. It's recognition.
What it can teach us
The practice this site is interested in is simple: listen slowly. The unsettling things kids say are usually not warnings. They are first drafts. They are language under construction. If you are around children long enough, you start to collect them — and you start to notice that the strangest ones often turn out, on a second pass, to be the most accurate descriptions of something you'd been ignoring.