In this interview with Magda Rodak Philippe Lejeune talks about the work of a researcher on autobiography and personal diaries. He recalls how Rousseau’s Confessions inspired him to write the first monograph on autobiography in France and to propose the notion of the “autobiographical pact” – the promise of telling the truth about one’s life. Lejeune also talks about how a manuscript by his great-grandfather, discovered in his house, drew his attention to autobiographies by ordinary people. This led him to study personal diaries (and to keep a journal). Lejeune appeals to the public to submit testimonies about how and why they keep journals; he conducts surveys and actively searches for diary manuscripts. He also talks about the functions of personal diaries, nineteenth-century women’s diaries, the multiple versions of Anne Frank’s diary and the activities of the French Association pour l’autobiographie et le patrimoine autobiographique [Association for Autobiography and Autobiographical Heritage], which he founded.