I learnt many new words while in Zanzibar. Amongst others, one that apparently describes me: "Mzungu". That's the Swahili word for Europeans, though quite derogatory. According to my new friend, Ussi, a venerable Zanzibari wiseman, the name comes from the "mzunguka", meaning "one who comes and goes", which was first used to describe the white explorers of earlier centuries, the likes of Vasco da Gama and David Livingstone. Today, the word is thrown around willy-nilly mostly by dala-dala drivers trying to make an extra couple thousand shillings off unsuspecting tourists who never stay long enough to know better. Zanzibar,...