There are two ways to feel close to someone. One way is to have social contact with him. You see him at a simcha, meet her at the supermarket, run into him after mincha. The second way is much deeper. You know that you are connected to this person [and he to you] without even talking to him. The first way requires an external expression. The second just IS, with no need for any concrete expression.
The Korban Pesach is a unique Korban. It is a Korban Yachid, a Korban of an individual [every individual is obligated to bring this Korban], but at the same time it is considered a Korban Tzibbur, a communal offering, because it is brought בכנופיא - everyone together.
The halacha is that the Korban may be eaten only at night. The reason for this is that at night it is dark and that prevents social contact between between people. So when we eat this Korban we realize that our connection to others is so deep that it requires no external expression. We are ONE SOUL. At night we eat this personal-communal offering to remember our eternal connection.
We can also understand another law. The halacha is that the Korban Pesach may be eaten only by those who have first registered to eat this Korban [and people split up into groups and registered on their respective Korbanos]. The reason is that in order to give expression to our deep spiritual connection it requires preparation and may not be done haphazardly.
Is that SOMETHING???
[עולת ראיה ח"א]