Mah Nishtanah (Why is it Different?)

Why is this night different from all other nights, from all other nights?
On all other nights, we may eat chametz and matzah, chametz and matzah.
On this night, on this night, only matzah.
On all other nights, we eat many vegetables, many vegetables.
On this night, on this night, maror.
On all other nights, we do not dip even once.
On this night, on this night, twice.
On all other nights, we eat either sitting or reclining, either sitting or reclining.
On this night, on this night, we all recline.