It's possible that:
* It's a relatively new or lesser-known poem: The poem might have been written by a contemporary poet, or even by someone who hasn't been published widely.
* It's a personal poem: Perhaps it was written by someone as a personal piece and not intended for public circulation.
* It's a fictional creation: It's possible that the title refers to a poem created for a fictional story or a specific context, making it non-existent in reality.
If you have further information, such as where you encountered the poem or any other context surrounding it, it might be easier to identify its author.