Lewis begins by introducing his intentions for this book: He will tell the story of his own spiritual movement from atheism to Christianity. In particular, he’s interested in writing about a feeling he calls “Joy,” explaining:

I have been emboldened to write of it because I notice that a man seldom mentions what he had supposed to be his most idiosyncratic sensations without receiving from at least one (often more) of those present the reply: ‘What! Have you felt that too? I always thought I was the only one’ (vii).

He explains that his book will be shaped around this purpose only and that it won’t be an autobiography in the full sense: He’ll give the most detailed attention to his childhood and confine himself to only the most relevant parts of his adult experience. The childhood parts, he says, are always the most interesting parts of autobiographies anyway.

Lewis tells us about his family background. He was born in Belfast in 1898. His parents were both well-educated and thoughtful people but very different in temperament. His father, a lawyer, was passionate and emotional. His mother was cheerful and level-headed. They had two sons, and Lewis was the younger. Lewis remembers preferring his mother’s way of being from a young age: He was embarrassed by his father’s intense and mercurial feelings.