Whatever Works (2009) on Netflix

In New York, the bitter and grumpy Professor of Quantum Mechanics in Columbia University Boris Yellnikoff is a snobbish and pretentious intellectual that claims to be a genius in String Theory and that the world is completely wrong. During an existential crisis, Boris ends his marriage with Jessica and jumps through the window to commit suicide. However the canopy saves his life and Boris becomes limp and quits his job in Columbia. He moves to an old apartment downtown and gives chess classes to children to make some money. When the simpleminded religious Mississippi runaway Melodie Saint Ann Celestine asks for food to him, he temporarily lodges the girl in his apartment. Along the days, the atheist Boris shapes Melodie to his thoughts and the girl, impressed with his pretentious geniality, fits his world. Despite their difference of ages, they marry each other and have a routine life. However, the world of Boris changes when out of the blue Melodie's mother Marietta arrives in their apartment.