Two quotes from The Poet's Notebook:
Mary Oliver: "Language, the tool of consciousness."
Charles Simic: "To be bilingual is to realize that the name and the thing are not bound intrinsically. It is possible to find oneself in a dark hole between languages. I experience this now when I speak Serbian, which I no longer speak fluently. I go expecting to find a word, knowing that there was a word there once, and find instead a hole and silence."
Language is not thought. We use language to translate thought to ourselves and others. All translation is fraught with error, yet we get our thoughts and needs communicated pretty well. It may be that we do this somewhat better than all other species and that relative success may be why we are currently the planet's dominant life form. On the other hand, there was a great expanse of ages in which humans used languages well and managed not to become Earth's dominant life form, an expanse of ages far greater than that occupied by what we call civilization. Maybe our victory is pyrrhic. The end of the (human) world has been predicted regularly over the millennia. One day one of those predictions will be spot on?
I haven't enough facility in a language other than English to evaluate Simic's particular kind of "hole and silence," but I encounter similar geography. My own searches are most obvious when I'm trying to pull up the name of a celebrity. When the blankness stymies, I start naming a star's movies in hopes whoever I'm talking with will be able to get to the name before me - or that this circling will reveal the name from a new angle.
source: The Poet's Notebook: excerpts from the notebooks of contemporary American poets edited by Stephen Kuuisto, Deborah Tall, David Weiss