Helen Keller wrote a very poignant account of living as a nonverbal child, having lost her hearing and sight as a young toddler, before acquiring more than a few words (most of which she forgot).
She has intense sensory and emotional memories of her experience, but also writes of deep frustration at being unable to really communicate or understand the world around her. Children are naturally more concrete than abstract thinkers before a certain age, but she was old enough to begin abstract thinking before she re-acquired language, and she definitely considered her lack of language to have dramatically affected her inner life:
“Have you ever been at sea in a dense fog, when it seemed as if a tangible white darkness shut you in, and the great ship, tense and anxious, groped her way toward the shore with plummet and sounding-line, and you waited with beating heart for something to happen? I was like that ship before my education began, only I was without compass or sounding-line, and had no way of knowing how near the harbour was. “Light! give me light!” was the wordless cry of my soul.”
You can find the full text of her autobiography online, “The Story of My Life:”
https://digital.library.upenn.edu/women/keller/life/life.html#I
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