Pregnancy and birth normally is traumatic and fucks you up. Your brain is doing wild things chemically and drowning in hormones, that sometimes actually push people into a temporary insanity. People with postpartum psychosis can become violent to themselves and others, hallucinate, have delusions, etc. It happens ~2 out of 1,000 births. And is more likely if the person had an untreated mental health problem beforehand. Getting angry that somebody cut you off is not a medical thing. Psychosis 10 minutes after labor usually is.