The start receives such disproportionate attention because it isn't deemed to be just one phase among many; for the Romantic, it contains in a concentrated form everything significant about love as a whole. Which is why, in so many love stories, there is simply nothing else for the narrator to do with a couple after they have triumphed over a range of initial obstacles other than to consign them to an ill-defined contented future--or kill them off. What we typically call love is only the start of love.