Symbolism, Imagery, Allegory
Going "down the rabbit hole" has become a common metaphor in popular culture, symbolizing everything from exploring a new world to taking drugs to delving into something unknown. (Think The Matrix, for example, where "following the white rabbit" and later choosing the "red pill" starts Neo off on a journey of philosophical realization from which he cannot return.) In Alice's Adventures in Wonderland, the rabbit hole is the place where it all begins. It's Alice's unthinking decision to follow the White Rabbit that leads to all of her adventures. The pop culture version of this symbol perhaps doesn't take into account the "unthinking" nature of this choice quite enough. After all, Alice's decision is pretty foolhardy; if this weren't a magical fantasyland, she'd probably be killed by the fall, and she has no idea where she's going, what she's facing, or how to get home. You may also notice that going down the rabbit hole is a one-way trip – the entry, but not the exit, to the fantasy world.