The line comes from Quentin Tarantino's 2015 Western The Hateful Eight, where Demian Bichir plays Bob, a Mexican man who says he is looking after Minnie's Haberdashery while its owner is away. When his story is questioned, he answers with this cool, skeptical retort. Short movie quotes like this travel well on soundboards and social video because they are instantly recognisable and easy to drop into an argument. Its direct challenge, delivered without shouting, keeps it useful whenever a creator wants to demand proof with humour rather than anger.