I think what happens after a relationship ends depends a lot on the person, the way the romantic relationship ended, and what, if anything, happened before the romantic relationship began. Examples:
1. If you were long term friends before being romantically involved, then the breakup can be a double blow, because you lose a lover and could also lose a friend. Reactions to that can vary person by person. For some it is too painful to continue as friends but not as lovers. Others slip seamlessly and effortlessly back into 'just good friends', with no bad feeling, and genuine joy for the other's successes in life, including new relationships and marriage to someone else.
2. Some people may hold out some hope that the relationship can be salvaged and rekindled, and so loiter in the background. This might be considered a form of orbiting.
3. For those who were not long term friends before becoming romantically involved, I think the likelihood is greatest that they will simply drift apart and lose contact (except when one holds out hope of rekindling the love, as described in 2).
Some of the reactions and outcomes I described above are healthy, while others could be indicative of someone who may need to work on themselves before pursuing another romantic relationship. I still consider myself a work in progress, but I'm curious to see what opportunities the Lord may provide to me in the future.