Example A:
James Spader
In
Pretty in Pink he is a pompous ass, sexually indulgent and blasé about it. Secretly falls in love with Andie (Molly Ringwald) but can't admit it. Realizes he is "shit", just like Blaine says and that Andie was too good for him. His self image falls apart.
As a result, after high school he drifts and becomes severely depressed.
Sex, Lies and Videotape. [really a great movie if you haven't seen it and it wont be what you expect, rent it] He processes his realization/breakdown in an eccentric way, but then learns something and accepts something about himself by the end of that film. (I'm being vague for those who haven't seen it)
Has a relationship for a while but his problems with intimacy resurface.
(I could mention
Crash right here but I didn't like the movie, and it's supposed to be set in the future, but it's yet another extreme of sexual misadventure typical of someone who is a manic sexual-obsessive-compulsive)
Spader's backstory for his character in
Secretary could be the history in these previous films.
Example B:
Scarlett Johansson
Rebecca, after the end of
Ghost World, goes to college, graduates and marries [Giovanni Ribisi]. In
Lost In Translation, the girlfriend she calls at the beginning of the movie is Enid. Charlotte's attraction to Bob is slightly influenced by Enid's relationship with Seymour, still feeling abandoned by Enid with whom she still subconsciously harbors a competitive jealousy.
Suddenly she travels back in time where she meets
Vermeer... no, wait... that doesn't work, does it.