It is the best type of independent movie. One in which life is still life-in the end, no matter how fantastic the story line is. There is always good and bad, happy and sad... everything comes at a price. Charlie never was of this world, anyway. He didn't play by its rules or enjoy the day-to-dayness of real life. He was almost a mythical creature and they don't adapt well in the real world. Miranda wanted to live in the real world with its things and surface stability. She needed that. So, they both got what they wanted, but there is always a price to pay.
Some of the success depended heavily on the actors, too. Hard to imagine the characters being done any better, including not only the dad & daughter, but Pepper too. It is Michael Douglas at his best; and I liked also the Evan R. Wood's performance.