Not fiction but I love this part in Feynman’s The Pleasure of Finding Things Out:

“When he was very small we used to rock him to bed … and tell him stories, and I’d make up a story about little people … they lived in the ventilator; and they’d go through these woods which had great big long tall blue things like trees, but without leaves and only one stalk, and they had to walk between them and so on; and he’d gradually catch on [that] that was the rug, the nap of the rug, the blue rug …”