When the Hagadda begins the answer to the Four Questions, it inserts אמר ר' אלעזר בן עזרי'ה... a general discussion about whether one is obligated to mention Yetzias Mitzrayim at night.
Now, of all nights, isn't the night of Pesach the one night in the year for which there surely is no disagreement as to this obligation? Why mention this discussion on Leil Haseder?
Actually, inasmuch as leaving one's personal Mitzrayim is a daily struggle, this discussion gives us the proper perspective on how to achieve this important objective – especially on the night of Pesach, during which the importance of the Jewish child is highlighted and celebrated.
To understand this, we must first accept the absolute necessity for the first and most basic requirement for true Yetzias Mitzrayim: the slave has to know that he is a slave and want to leave his slavery. Without this, even Moshe Rabbeinu cannot set him free!