Years later, my grandmother would still tell people that I learned to swim in a movie star’s pool, though she always said this with the same slanted tone and pinched expression she used when telling people that my mother dated only rocket scientists or that my grandfather was a real Mr. Fix-It around the house, indicating there was significantly more—or rather, less—to the story and leaving me to explain about Gretta Benson-Klein-Huffacher and how she wasn’t really a movie star, just an old lady who hosted a show for other old ladies on public-access television. Gretta had, many years…