Lenderman turns a breakup promise into a threat. The narrator keeps saying "we'll be perfect," but the only version of perfection the song actually describes is becoming strangers. Every reassurance is a demolition disguised as comfort.
We are reasons so unreal / We can't help but feel / That something has been lost
The vagueness here is the point. Nothing specific caused this, which means nothing can fix it. "Reasons so unreal" sounds like a way to avoid saying "we stopped trying."
So far I still know who you are / But now I wonder who I was
The pivot from "you" to "I" is where the real loss lives. He's not grieving the relationship. He's grieving whoever he was before it ended, which is somehow worse.
We'll always be good friends / The letters have been sent on
"The letters have been sent" sounds final, like court documents. Not "I sent you a letter." Just the passive fact of paperwork already in motion. The friendship promise lands hollow when the bureaucracy is already done.
Strangers on the street / Lovers while we sleep
This might be the song's one honest moment. Awake, they're nothing. Asleep, the muscle memory hasn't caught up yet. The only place the relationship still exists is unconscious.
The word "perfect" appears nine times. The word "love" never does. That swap is the whole song. He's convinced himself that promising perfection is kinder than admitting what actually happened, which is that they're already gone.