I have two:
In one I am trying to crawl up a long thin subterranian tunnel, so tight that I can barely struggle an inch at a time, while I am aware of a raucous party above me, so loud that no-one can hear me calling for help.
In the other I am back at school desperately telling them that I am 40 years old now and don't have to be there.
Obviously isolation and a sense of powerlessness play a powerful role in both.