Brian Sutton-Smith, who spent his life studying play, believed that “the benefit play accords each child, who gains confidence in a variety of . . . pretense forms and thereby develops an inner, subjective life, [is] a life that becomes the child’s own relatively private possession . . . . [T]he earliest pretend play . . . serves as the basis for their development of the duality of private and public that we adults take for granted.”