I wonder if it's something to do with the memory being reinforced (maybe in surprising ways). E.g one of the memories I have from around a similar time is me receiving a toy gift (video memory) . It makes for a decent display item and has been kept out in one bedroom or the other in every house my family lived in since. So I would have seen it every now and then throughout my childhood. Perhaps, this reinforcement can occur in other, more non-obvious ways in a child's brain, offering a similar explanation for your experience.