Examples of not seeing the trees for the forest are flyover assessments of sociological regions or general assessments of human psychology.
A more detailed example of this pertaining to psychology might be the following description of Borderline Personality Disorder:
People with borderline personality disorder are unstable in several areas, including interpersonal relationships, behavior, mood, and self-image. Abrupt and extreme mood changes, stormy interpersonal relationships, an unstable and fluctuating self-image, unpredictable and self-destructive actions characterize the person with borderline personality disorder. These individuals generally have great difficulty with their own sense of identity. They often experience the world in extremes, viewing others as either “all good” or “all bad.” A person with borderline personality may form an intense personal attachment with someone only to quickly dissolve it over a perceived slight. Fears of abandonment may lead to an excessive dependency on others. Self-multilation or recurrent suicidal gestures may be used to get attention or manipulate others. Impulsive actions, chronic feelings of boredom or emptiness, and bouts of intense inappropriate anger are other traits of this disorder, which is more common among females. (Source)
I have no doubt that this general description of the “forest” of BPD is somewhat useful as a flyover take on a psychic region that seems to have its own reality within American culture. The same link concludes that “there is hope” for personality disorders if we come to “understand that they are illnesses.”
Thus, a general remedy is assigned to a general “illness”; a semiotic contortion is assigned to the category “hope.”
TBH, as a Buddhist I must say you really should “have difficulty with your own sense of identity” because there is no such thing. Sentience in all its guises is dynamic and ever-changing.
You actually do not need a “self-image” at all. So if the one(s) you keep trying for are “unstable and fluctuating,” you are probably seeing reality more clearly than people whose “self-images” are stable and not fluctuating!
The fundamental problem with BPD and Narcissistic Personality Disorder, two of the most difficult disorders to cure, is in the trees. It is good to see the forest and know where it lies within the terrain of the sufferer’s culture, but the problem of any individual suffering from either of these disorders is always going to be in their trees.
So what are the trees? They are the actual signals received by the person, sent out by the person, and used internally by the person.
Those are the units that best describe what a sentient being is and does. If you can’t fix the trees or treat the trees, the forest will never be healthy.