you are

You are the white bear I try
not to think about, the file
untitled in my computer's cache:
you are the one piece of a puzzle
already burned, the rhyme no
sentence of mine ever leads to.

You are the erasure leaving
an impression, blank, on each page
of my pad, phone number with no
name, connection that can't find
its voice, the carryover never
cancelled, not to be restored.

You are the amputee's ghost
pain, the debt redoubled on
full payment, the dissolving
membrane whose unfriendly floaters
blur my lens, the emperor's new
son and heir, the lost white bear.

[W.D. Snodgrass, 'A Presence', from Not for Specialists: New and Selected Poems

The bear is a reference to Fyodor Dostoyevsky, whose older brother "sometimes made him stand in a corner, telling him, 'And don't think about a white bear!'"]