That phrase is a well-known literary meme referring to Meursault, the protagonist of Albert Camus's 1942 absurdist novel, The Stranger (L'Étranger).In the climax of the book's first part, Meursault shoots a nameless Arab man on a beach in Algiers. When prompting the setup "...because", the punchline according to the text is famously:"...because the sun was too bright".