One of the most important Mitzvot related to the exodus from Egypt, as well as the Pesach holiday, is telling the story of the redemption.
This is learned from the words, והגדת לבנך, “and you shall tell your son.” It is explained by the Sefer Hachinuch that there is an obligation on Seder night to speak of the great miracles that took place in Egypt. This is extended to the point that we are urged to act out the story, where we went from being oppressed slaves to free men.
Aside from specifically doing this on Passover, there is a rabbinic obligation to mention the exodus every morning and evening. We are never to forget these great events every day of our lives.
The significance of these outward miracles is a confirmation of how we began as a nation. No religion in the history of mankind, can make the claim that when they began, G-d revealed Himself with signs and wonders.
In essence, the daily mentioning of Egypt, is a confirmation of the truth of Judaism. When we began, it was necessary for Hashem to reveal Himself. Since then, we still see miracles, but more in a secret manner.
We can now clearly understand why the mentioning of Egypt is such an important Mitzva.