A particular alchemy exists within the confines of a black box theater, where the absence of spectacle forces an audience into direct communion with raw human truth. At Theater for the New City, Patricia Goodson’s “Remembrance” harnesses this intimate power to devastating effect. The production eschews theatrical artifice in favor of something far more precious: authentic emotional resonance. Indeed, this stark examination of caregiving amidst the cruel progression of Alzheimer’s disease offers audiences an experience that is at once harrowing and strangely affirming.