the word for this

I am that word
in the far back left
of your mind
you can't reach
or catch
or get
or find

Or define,
but you know what it means.
You know there's a word, and
it's perfect.
It seems

but you grope in the dark
and you strain heart and mind,
and it seems just as far
as it ever was

And it starts to feel like
it never was there
to find.

There was no such thing,
just connection misfire,
just deja vu. Just fine.
Giving up,

just

because.
It will come to you
in time.