4 ideas
He comes to believe he was Pedro McEvoy, a stateless man with false papers, whose lover Denise Coudreuse vanished in winter 1943 when smugglers abandoned the couple in the snow near the Swiss border. That abandonment appears to be where his memory broke off, and the novel ends with an unfinished trip to an old address in Rome, rue des Boutiques Obscures.
A man appears in the background of thousands of holiday snapshots for forty years, always in a swimsuit, yet no one knows his name or why he was there. Most lives leave a person's image in other people's records rather than a record of their own, so identity survives only as unexplained presence.
He infers it from boxes of old photographs, address books, bills and other people's partial recollections, each of which may be mistaken or may concern someone else. Seen this way, a self is a hypothesis built from external evidence, held tentatively, with gaps that stay permanently unverified.
The novel's missing people are émigrés, holders of forged passports and drifters with invented names and nationalities, whose fragile legal identities made them easy to lose during the Occupation. When the papers, the addresses and the witnesses are gone, the person effectively ceases to exist, even to themselves. Personal amnesia is shown as the individual version of a historical erasure.