Melanie's problem isn't that she's lonely and lacks social skills, or that other people refuse to reach out and help her; it's that she's a sociopath. Here's the dictionary definition of a sociopath: "A person with an antisocial personality disorder, manifested in aggressive, perverted, criminal, or amoral behavior without empathy or remorse."
Melanie lies constantly; she almost never tells the truth even when there's no good reason not to, as when asked what her plans are for the evening or the holidays.
She aggressively invades other people's lives with no sense of interpersonal boundaries, of other people's right to live their own lives without her. She invades social gatherings to which she has been told she is not invited, and she shuns those to which she HAS been invited. She stalks, spies, listens outside doors and windows, pushes her way into other people's houses.
She never sees anything wrong in her OWN behavior - the problem is always somebody else's failure to give her what she needs. She is entirely consumed by her own needs and completely blind to anyone else's needs. She has no business teaching children. She needs intensive psychiatric treatment.
She does NOT need for other people to be more compassionate toward her. They ARE compassionate, but she either rejects them because she finds them unattractive (Thorsten) or pursues them and violates their privacy so aggressively (Tina) that she kills their compassion.
None of these are signs of a normal but shy person, or of a person who simply hasn't had much practice socializing with other people. These are signs of a person with a serious, deep-rooted and potentially dangerous personality disorder. The fact that even her own mother doesn't want to talk to her shows that her behavior problems did NOT suddenly begin when she moved to Karlsruhe and her new job.
She needs a good shrink, not friends. In her present state, she's incapable of friendship or any other normal personal relationship.
This is a very good movie, because I and nearly every other reviewer - even those who give the movie bad ratings - relate to Melanie as if she is a real person. Like it or not, this movie does what movies are supposed to do: create a world which the viewer experiences as real.
