Cause I won't be waking up, my dear > Time has run its course > Happy anniversary > Now I'll say goodbye, my dear > This will be our last > Happy anniversary With a knot in your stomach you almost feel shameful about your previous interpretation as you try to hold back tears.">
I'm not sure if it's intentional, but I think part of the power of this song is that at first it can be misconstrued as a breakup song, and then at some point there is a sobering paradigm shift where you realize that it is actually much, much darker than that.
Let me try to walk you through this experience:
I left out a few lines, but you can see that it is possible to interpret this first stanza as a couple, perhaps married, who are in their bedroom having an argument. And while there is love, the couple has realized that the relationship cannot last.
Even after this stanza the interpretation holds. The relationship is ending; one of them is moving out. Ironically, it is happening on or near their anniversary. Again they don't hate each other, but they know it must be done.
Perhaps the first clue is here. But still, struggling to breathe could be something that happens when you are crying or having an emotional crisis, which is understandable in the situation of a marriage falling apart.
At this point in the listening experience, your eyes widen a bit and you start thinking "wait a minute..." You start trying to remember the words from the beginning verses but before you can, Justin launches into the final stanza:
With a knot in your stomach you almost feel shameful about your previous interpretation as you try to hold back tears.