This reminds me of Nietzsche's profound statement: "If you look long enough into the void the void begins to look back through you."
This poem seems to be at that moment when someone realizes that they are looking through the void; the impact of that & how consuming it can be, so suddenly. I also like how fully present it is, & how it amounts to nothing in a way; that Zen way. The verb "lost" adds a complexity though that can't go without noting, & I think that there is always that lost feeling when we are startled by a realization.
I also really love that beginning line. It is odd, & made me stop to ponder what that could mean.