Hollywood blockbusters love pop psychology, using widely-accepted psychological concepts to explain a dramatic idea or a character's actions. Fifty Shades ladles it out in the most outrageously piecemeal and obvious fashion, revealing that Christian was in a submissive relationship with one of his mother's friends for six years, from the ages of 15 to 21. As such, his desire to find a submissive for himself is him clearly craving the very control that he lacked as a youth, when he was abused by an elder. Rather than simply allow Grey to be a cool, collected businessman with a penchant for the kinky, James felt the need, as so many modern writers do, to explain every last detail of a character's mindset, because everything has to have a dark reasoning attached to it rather than "just because". While the abuse itself is far from funny, that the movie takes such a pat approach to it certainly is. Plus, referencing clear sexual abuse in a movie that's supposed to be sexy? Probably not a great idea...