Dreams no longer come wrapped in the old mystical fog. We have a name for the stretch of sleep in which they most often appear: REM, rapid eye movement sleep. It takes up roughly 20% of a night’s sleep and tends to show up more often in the latter half of the night.
In general, after a person passes through a full cycle of light sleep, REM, and deep sleep—about an hour and a half—it is difficult to know that a dream happened at all. But if you happen to wake in the morning during the REM part of a sleep cycle, the dream you were just inside may still be there, fresh enough to remember.
This also means that dreams are not naturally linked to one another. Those rare dreams that feel like a serialized drama, one episode after another, are usually the result of waking during REM and then falling back asleep quickly enough that the larger sleep cycle is not truly broken.
There is an old almanac near me. In one tiny corner of each page, it carries a brief entry from the tradition of Zhougong’s dream interpretation: “If you dream of this,” then “it foretells that.” The only unscientific part is not even the superstition itself, but the way it appears every day, page after page. If the calendar page is torn off each morning, how is anyone supposed to confirm whether the previous night’s dream happened to match the entry written there?
Suppose that on some future page, the dream omen says: “picking chestnuts.” How could I possibly anticipate that on that exact night, my dream would be precise enough to put me in a tree, picking chestnuts rather than anything else?
I once knew someone who would wake up every morning and check Zhougong’s dream interpretations. For a while, though, he said he had no dreams at all. I explained that he had probably been waking from light sleep and therefore could not remember them. He preferred another explanation: his “spiritual power” was insufficient.
I should add that he believed his dreams had prophetic ability.
When science failed to persuade him, I tried turning science into bait. I told him that if he calculated his sleep in multiples of 1.5 hours and set an alarm for the REM period, he might be able to wake up from inside a dream and catch it in the act.
Did it work?
I don’t know whether you have ever forced yourself to locate the exact border between being awake and falling asleep. The harder you try to find that seam, the more alert you become, until sleep withdraws completely. Trying to prove REM exists in your own bed can easily bring on serious insomnia, and even REM sleep behavior disorder.
This friend really did set alarms according to the sleep-cycle theory, trying to wake at the precise moment of dreaming so he could remember what he had seen. At first, it worked a few times. But slowly, the obsession did the opposite of what he wanted. He began to lose sleep. Later, it developed into REM sleep behavior disorder: talking in his sleep, acting out movements from his dreams, even sleepwalking.
To bring him back to ordinary life, I told him that REM sleep behavior disorder is in fact an early manifestation associated with Parkinson’s disease. After that, what he fought was no longer forgetfulness, but dreams themselves. He did not want to dream anymore. He stopped thinking about so-called prophetic dreams.
Is this story true? That depends on whether you choose to believe it.
He was only caught by the same spell that can catch any of us: an obsession lodged in the narrow gap of dreams, waiting at any moment to swallow reason whole.