There are these moments when you first wake where your senses haven't yet started to flood into your conscious perceptions. In those moments, the dream world usually starts to loose detail and fade away. You were just with someone and there was joy in it. You can't recall their name or their features just the sense of loss as your rational mind takes control and begins to organize your day.
That joy that will never be repeated in the same way is true scarcity, the original ephemeralism.