The following are the twenty most frequent dream themes recalled by 1181 Canadian and 1186 Hong Kong college freshmen (most frequent first):
Note that these vary greatly in realism. Some are common events, and some are rare events that were were important for our ancestors. Some are about events that never actually happen: flying, being a child again, person now dead as alive, being in a story. Many of these are tied to rare extremes, especially negative extremes. The themes of arriving too late and failing exams are strikingly modern, and suggest that we industrial folks are often quite traumatized by our era’s event timing and school exam requirements.
Actually, I think the dreams are training us. Note that cats dream about cat stuff like catching mice and cat fights. Makes sense that we dream about ... taking tests. See here for more: https://www.amazon.com/Stor...
I can attest to feeling mildly traumatised by the industrial era's heavy use of scheduling, and by alarm clocks in particular.