Grease is a brutally honest and realistic depiction of teenage life in 50s America. Using documentary techniques to show what life was like for the millions of post war baby boomers, it never once deviates from its verisimilitude until the very end, when they all get into a flying car and depart for the skies. While of course, Grease is a candy coloured musical fantasy, the flying car bit always sticks out for pushing it too far. Director Randal Kleiser has reportedly and quite fairly answered questions about why it ends like this with a simple Why not? , but it does suggest that the entire ending is just one more extended day dream, and the whole thing never happened. Danny grows old alone.