a breakup based on the fact that there is no excitement in the relationship? the speaker has become so familiar to their other half that their other half begins to dismiss them as having "fallen into place", there's no mystery and nothing to learn anymore and this bores them. the speaker, quite understandably, doesn't get it. why would you leave give up someone you love just because of their familiarity to you?
a breakup based on the fact that there is no excitement in the relationship? the speaker has become so familiar to their other half that their other half begins to dismiss them as having "fallen into place", there's no mystery and nothing to learn anymore and this bores them. the speaker, quite understandably, doesn't get it. why would you leave give up someone you love just because of their familiarity to you?