Just watched this with my movie theatre-working friend and his grown nephew. Joseph Gordon-Levitt wrote, directed, and stars as the title character, someone who gets any woman he wants when going to clubs with friends but gets unsatisfied compared to the porn images he looks up on his computer while getting off. Since he's Catholic, he also confesses to a priest every week for these transgressions and does his penance while lifting weights. When he meets Scarlett Johansson, she doesn't take to him right away so he tries harder with her. She seems to want to change him or at least wants him a certain way based on the romantic movies they go to which he doesn't like but holds his tongue concerning those. It's at night school, which the Scarlett character suggested to him, that he meets another woman played by Julianne Moore who might also change him, perhaps for the better. I'll stop there and just say that while I was fascinated by the repetition of certain scenes in order to get the gradual humor that results when those scenes start changing routines-like especially during the climatic family dinner table scene involving dad Tony Danza, mom Glenne Headley, and sis Brie Larson-it's when things take a more dramatic turn that things get really interesting. Like those concerning the Moore character. So on that note, Don Jon is worth a look if you're interested in the mature subject matter.