Cross Wires and Razor Edges

As a 6 or 7 year old kid I remember the same kind of thing happening to me. The day after my birthday (where my lasting memory was a three tier sponge cake filled with cream and jam) I was in school and the teacher was discussing sponges under the sea. I couldn't for the life of me figure out why anyone would want to put a sponge under the sea (my mind still locked onto the vision of a creamy sponge cake), it would just get all soggy and horrible. Anyway I didn't bother to question this at the time and just put it to the back of my mind. While I wasn't thinking about this night and day, still it was maybe a year or more later before my doubts were answered. One day I was watching a nature program on TV, and the subject matter being discussed was natural sea sponges, it was then that the penny dropped as to what my teacher was talking about all that time before.