It took a few days of moping around the house before I finally acknowledged what the problem is: my heart hurts.

It's an expression I use with those closest to me. It means I'm sad, and to some degree I feel helpless. It means my heart is breaking just a little. And it's also an unusual feeling to have right now because I'm filled with anticipation and I'm more than a little excited: After almost six years I'm changing jobs—and it's a great opportunity to work more closely with the subject that continues to hold my attention: the spread of technology. I am excited. But the fact remains I have to say goodbye to some people who have come to mean a great deal to me. And I'm not sure how. What I do know is that my heart hurts.

Even the most stable social networks are not immune to change. People move and life events place them in different roles, and as they do, their responsibilities within their various social groups also change. In this way a person can be many things to many people even as she is many things to the same person—the roles of writer, colleague, wife, sister, friend, bibliophile, cook, caretaker, etc., all have different meanings in different social contexts, and different responsibilities. What does it mean if this role is suddenly removed from its social niche? What does it mean to the group and to the individual herself if she is to leave the network? The role may ultimately be replaced, but before it can be, the change has to be acknowledged. So we say goodbye.

Goodbyes have a particular role to play in mediating the balance of the network, and they often reflect the degree of change the group will experience. For example, if you're headed out the door to pick up a pizza for dinner, you might say "Be right back," or if you leaving a friend at the end of a night out, "See you later" could suffice. Both of these types of goodbyes indicate that the shift in the network is small and temporary. It's acknowledged that the person may be departing, but that they're expected back—and will soon occupy their place in the social group again.

But for long-term departures, more formal ceremony is needed. If the actual word "goodbye" has a sense of finality to it, it's not by accident. It's a contraction of "God be with ye," which conveys a blessing or prayer or hope that the person upon whom it's bestowed will travel safely. It's almost a plea. Today's assorted methods of electronic communication mean that separations are only as permanent as they are allowed to be, but there was a time when departure from loved ones forced you to consider the very real possibility that the parting could be permanent, or very, very, very, very extended. The gravity of this occasion was marked by a ritualized send-off in the form of a party or feast or an observance of some sort. From wakes to wedding receptions to going-away parties, the network must gather to reconcile the interruption to the existing connections. People meet and engage in exercises of remembrance which reinforces the sense that change is impending.

In the case of long-term goodbyes, rituals also serve to confirm the connection of the individual to the group, which is particularly important because in leaving an established network, she'll enter a transitory stage. Oh sure—she'll have a new role assigned to her and new responsibilities but there will be a period of adjustment before she truly belongs to the new network. Even if she's leaving to take on the same role elsewhere (e.g., cook), she'll still have to learn the nuances of that social order. But once you know someone, it's hard to unknow them—you might grow apart, your relationship might change, but if you know someone, have chosen to know someone and recognized her role within your network, you will always know that person. Rituals associated with long-term partings confirm deep rooted connections with the group.

Goodbyes can consequently become an exercise in expressing intimacy. Goodbyes between close parties are scripted. Does the following sound familiar? "It's getting late. I need to go." "Oh no. Stay for just a little while longer." Indeed, stay a little while longer while the other finishes his drink or because dessert hasn't been served or because another guest hasn't arrived—stay because your company is valued. While this example may relate more closely to a temporary parting, the idea that the leaving should be protested in some way to confirm the individual's meaning to the group is a routine part of goodbyes between close company.

At a formal gathering, not all members may cluster around the departee to offer objections—this responsibility falls to those closest to the individual—but those that do express dismay at the change may do so in the form of guilt or anger or sorrow. These emotions, similar to the plea to stay just a little longer, function to remind the individual has contributed to the network and will be missed. A lot can be conveyed by a failure or an unwillingness to protest in some form—and really, if a meaningful connection doesn't exist between separating parties, goodbyes can be short and completed quickly. The parting process is delayed between members for whom the separation will create the greatest interruption.

At the end of the day, it's not an easy experience for anyone. Goodbyes, especially among an affectionate cohort, can weigh heavily on the group dynamic, which is why it bears repeating that they are only as final as you allow them to be—after all, there's always Facebook.