I have nightmares caused by physical pain which is the result of a lifelong chronic illness. The night before I have a flight from a US airport, the pain nightmares invariably involve the TSA (perhaps as a result of two actual incidents in the past where they caused me so much pain that I almost fainted, and I have a high pain threshold)

I fly at least once a week in 'rest of world' and never have those dreams about screeners in other countries and don't have those dreams the night before I fly from other countries.