You know I felt this way for years. I felt that way through psychopharmacology in pharmacy school, and I felt that way during our psychiatry and behavior lectures in medical school. I felt like psychiatry was minimizing behavior to these boxes was far too reductionist. Then I spent a month in an inpatient psychiatry facility as a third year medical student.

While I completely agree that each individual is unique and people are more than their diagnosis, you'd be absolutely shocked by just how similar patients' overall stories, maladaptive coping mechanisms, and behaviors are within the same psychiatric illness. I can spot mania from a doorway, and it takes less than five minutes to have a high suspicion for borderline personality disorder. These classifications aren't some arbitrary grouping of symptoms: they're an attempt to create standard criteria for a relatively well preserved set of phenotypic behaviors. The hard part is understanding pathology vs culturally appropriate behavior in cultures you don't belong, and differentiating within illness spectra (Bipolar I vs II; schizophrenia vs bipolar disorder with psychotic features vs schizoaffective)