once a willful child who, like many willful children, felt most secure at home, has grown into an extravagantly social and nonconforming adult, one who creates camaraderie out of bus timetables, refuses to trouble herself when people look askance at her--and, in a buoyant refutation of the notion that mental retardation equals sluggishness, zips about jauntily to her own inner beat. My sister (my sister! I boast to myself) maneuvers through the world with the confidence of a museum curator walking approvingly through her galleries, and, far from bemoaning her otherness, she exults in it.