This cracked me up - watching the Narnia TV series as a kid they were made out to be so good, I would try to imagine what those semi-transparent cubes could possibly taste like. However, my reaction when I finally tasted them I think was opposite to what it seems you're alluding to: I think the anticipation and the immense respect I had for Lewis and Narnia in general made it so that they tasted better to me than they otherwise would have!