Huffing and puffing, you arrive at the train station just in time to see the last train of the day pull out of the station. What is your next move? Do you call the head of the transportation authority and demand that they send another train for you? Probably not. It would be naive to demand a new train just for one person, or even a few people, who showed up late.
Let's take a different scenario. You ordered a taxi to take you to a destination, but you're not particularly eager to go. If the taxi is late, will you call the company and demand that the driver hurry up? Again, probably not. If you're not that eager to go, then the delay might just be the excuse you were looking for to stay home.
A person makes a request only if he believes that his request has a chance of being honored, and if he wants the matter badly enough. Otherwise, he will not go to the trouble of making a request.
The first year after the exodus from Egypt, there were a few people who missed the opportunity to eat the Paschal offering in its proper time, on the night of the holiday. They approached Moses with a complaint: "Why should we miss out?" Why should we be denied the merit of eating the Paschal offering?
On its face, their request was a strange one: With all due respect to them for not wanting to miss this once-a-year opportunity, how could they fight the reality that Passover had already passed? What exactly were they expecting? To celebrate Passover on Shavuot?
Perhaps those people had faith that simply by presenting their request, something would be accomplished. Their desire to fulfill the mitzvah of bringing a Paschal offering was that strong.
And their approach proved itself: G-d accepted their request and established a new holiday, called "Pesach Sheni." This holiday was established for generations as a second opportunity to bring the Paschal offering, if one missed the opportunity to do so the first time around.
During the time of exile, the holiday of Pesach Sheni has no practical rituals beyond the token eating of matzah. However, the day holds a profound moral lesson: to believe in our own power to present a request and have it fulfilled.
In a typical day, we bring dozens of requests before G-d. Three times a day, we say the amidah prayer, with 18 blessings and requests. Many of those prayers are for the Redemption: We ask for the rebuilding of the Holy Temple, for the restoration of the Davidic dynasty, for the ingathering of the exiles. In Grace after Meals, which we say after every meal with bread, we also mention our desire for Redemption.
Our sages wrote the prayers the way they did because they knew that G-d desires and awaits our prayers. Our forefathers in the desert presented their demand because they did not want to miss out on one mitzvah. But as long as we are in exile, we are missing out on many dozens and hundreds of mitzvot. It is time for us to step up and demand, "Why should we miss out?" And, just as our forefathers experienced in the desert, G-d will heed our request and send us the complete Redemption.