In the haggadah we read that every person is supposed to view themselves as if he himself left Mitzrayim. This does not require imagination; rather, we need to view ourselves as part of the chain of Klal Yisroel, part of a whole entity that was redeemed from Mitzrayim. It is a matter of our identity. Our tool for conveying this is the power of speech, as we tell over the story to our children. Through the positive power of speech, we are able to build a sense of connection and identity, and know that we are part of something greater, a nation that is bound by a covenant with Hashem that spans time.