I have this childhood memory of my grandmother. We’re sitting in the grass outside her cottage in the North of Johannesburg, looking down the hill across the cracked concrete tennis court, onto the vegetable garden, and out at the manmade forest beyond, peppered with the purple blossoms of the Jacaranda trees. We’ve picked flowers from her garden and we’ve paused to admire and compare our bounties when she comments on the soft skin of my forearm, pinching it gently between her fingers.“Your skin...