First, I want to make one thing absolutely clear. For Jewish people, Pesach is the most significant holiday of the year. The seder, the Passover meal, is perhaps best compared to Christmas or Thanksgiving - if you're not there, you just know your mother will never forgive you. Ever.
However, the seder is much more than a meal. It's a ritual, complete with its own book, its own, bizarre little dishes, and its own songs and prayers. It's also worth keeping in mind that although some of the elements are always the same, no two families have the identical seder. Secular and extremely disinterested Jews might make do with a takeaway and a piece of matzah, whereas those more religiously inclined quite easily stay up til three in the morning, making sure that every word is read, every parsley stalk eaten, and every song sung.