Going in Style (1979)

Senior citizens Willie (Lee Strasberg), Al (Art Carney) and Joe (George Burns) lead lives of uninterrupted boredom until they alight upon the idea of robbing a bank together. Though none of them has a criminal record, they nevertheless find the planning of the caper an energizing and satisfying experience all around. Even more surprisingly, they pull it off -- but no sooner do they make off with the loot than their age begins to catch up with them.