Relationships between adults are almost always voluntary. It means that the relationships can flourish only when both the people want it, and put the effort needed to nurture it. On the contrary, it needs only one person to walk away for the relationship to collapse.
Some relationships are given to us (with parents, siblings, children, relatives) but most others we form them in schools, colleges, workplace, leisure activities etc. Ideally we might think that all relationships should last a lifetime but life does not operate that way. Many of us when in school/college think we are going to be friends forever with some people. When we grow up and grow apart with the distance and time the relationship withers away. Sometimes when we meet some old friends, with some of them, we don’t have much to talk about except rehashing the past. How often can we do that? Should we struggle to maintain such relationships at any cost? Or can we accept the relationship was good in the past but today it is past its expiry date?
When we are working, we might cultivate some great relationships with some of our co-workers. When either of us move away from the workplace, it is possible that our interactions come down drastically, we have new coworkers and the old relationship does not have any more currency. Whether we acknowledge it or not, the relationship is past its expiry date.
Hard as it is to accept or acknowledge, some of our given relationships with our blood relatives, a spouse or an ex-spouse can also fall apart. As a child we did not have any options, we were forced to have a relationship with our parents, siblings, blood relatives etc even when one of them was abusive. But as an adult now we can make a choice. Do we want to maintain a relationship because it was given to us or can we say now as an adult I choose not to have this relationship? Unless there are reasons, a relationship with an ex-partner, ex-spouse can also reach an expiry date.
In an ideal world our relationship with people may be for life, but in real life, when we feel a relationship has reached its expiry date, it is okay to acknowledge that and move on without any regret.