Back around the mid-60s or so, I read an anthology of SF/Horror short stories. I think the anthology title was something like "Third From The Sun" (no, not "Third Planet..." nor "Third Rock...)
One of them was very short, maybe 5 - 10 pages long.
The very first line (if I recall correctly) was "You wretch she said." It was told from the POV of a kid who is kept locked in the basement by his parents, for many years. The parents are scared of him for some vague reason, and they are ashamed of him, but they don't send him away. I think the kid fantasizes about killing them and escaping.
The punctuation is bad, and there are no quotation marks when he quotes the parents. It's almost as if we're reading his journal and his literary skills have been sorely neglected.
Does this sound familiar? What's the title, and who was the author?
For some reason, I keep thinking of Robert Bloch, but don't recognise the title in any lists of his work.
Something like "That Only A Mother", but that's a different story, by Judith Merrill.