Meet Si, a young man coming of age in apartheid-era South Africa. Si is juggling family, friends, and girls-but he must also figure out how to manage the demands of Andrew and Benson.

"Andrew" and "Benson" are the manifestations of Si's undiagnosed bipolar disorder. Andrew, a devil-may-care bloke, is what Si has dubbed his manic moods. People enjoy being around Andrew for the thrills, but he's unable to form any deep attachments, which can be off-putting. Benson, on the other hand, represents Si's darkest days.

In this fascinating account, Si recounts his journey to diagnosis and...