Romantic separations have always struck people with a kind of astonishment. A great many songs have been written about the inability to believe that something so good has ended.
And that fact — that it can end — can take you to two opposite positions.
The first: if it can end anyway, it is a waste of effort in advance. Let us enjoy ourselves, move from bed to bed, and go with the flow.
The second: if it can end, then perhaps I had better not take love for granted. Perhaps it is worth investing in it every day. If this is something that protects me, I will handle it carefully.
Both positions are drawn from exactly the same observation, which is what makes the choice between them interesting. Nobody is being naive and nobody is being realistic. The fact of impermanence is agreed on both sides; the two positions differ only in what they conclude a person should therefore do with their attention.
And here is the thing to notice about the first. It presents itself as the tough-minded option — as a refusal to be sentimental about what the evidence shows. In practice it is the more protected of the two. It arranges a life in which nothing is ever at stake, which means nothing can ever be lost, which means the astonishment that started all this can never happen again.
That is not realism. It is a fairly expensive insurance policy, and the premium is everything the second position produces.
In the long run, most of us understand which position is better for our happiness and our resilience. Rather fewer of us act on it before something has been lost.