I don’t quite know how Ryan the Nephew learned about the concept of ghosts. Earlier on, his parents decided to shield him from supernatural beliefs for as long as possible. Such things were deliberately never mentioned in front of him because kids as you know, pick up things way too easily. It is also psychologically unhealthy, but that’s another topic for another time.
Anyway he did pick it up, probably from his kakak and/or playground friends. He’s also rather adamant that ghosts exist even though I’ve been half-heartedly trying to make him drop the idea. Here’s him telling me a ghost story then not wanting to befriend me after I told him that it was bollocks. Not in those exact words, but you know :)