Gary Sheller's (Martin Freeman) days in a successful band with the world at his feet are a distant memory. Now he spends his days writing ad jingles for his best friend (Simon Pegg) before going home to a relationship that is just as unfulfilling. But when he learns to control his dreams, he discovers a whole new world of beautiful women and endless possibilities. It's there that he meets the woman of his dreams (Penelope Cruz). But when the lines between his fantasy world and reality start to blur with hilarious consequences, Gary finally has to wake up and smell the coffee.