I dreamed it and it happened: why it feels like premonition

The short answer

Dream interpretation is not prediction and not diagnosis. This article separates what sleep research observes from what popular interpretation associates with the theme, always saying which is which.

When a dream seems to come true, there is almost always a combination of three things: we dream much more than we remember, dreams tend to deal with real worries that were already in the air, and memory adjusts the dream after the event happens. No reliable research has shown that dreams predict the future, but there is also no need to dismiss the impression of someone who lived through it as nonsense.

Whether or not to believe in premonition is a personal matter and, for many people, a matter of faith. What science offers is an explanation of why the experience is so common and so convincing. If the dream was about someone dying, first read what it means to dream about death, because that is the case that frightens people most.

Read also: The reason behind déjà vu and Recurring dreams.

Many dreams, few remembered

A night of sleep has several cycles, and REM sleep, the stage most linked to vivid dreams, comes back a few times. William Dement and Edward Wolpert, in 1958, saw that people woken during this stage usually report dreams. Most of those dreams, however, are gone before breakfast.

How much people remember varies a lot from person to person. In a 2014 study by Jean-Baptiste Eichenlaub and colleagues, high recallers reported on average about five dreams a week; low recallers, about half a dream a week. Now do the math for the first group: that is hundreds of remembered dreams a year, each one with people, places and situations from everyday life. It would be strange if none of them resembled something that is going to happen.

And nobody mentions over Sunday lunch that they dreamed about an accident and nothing happened. Those dreams are forgotten, and only the ones that "hit" become stories.

Sources: Dement and Wolpert, Journal of Experimental Psychology, 1958; Eichenlaub and colleagues, Resting brain activity varies with dream recall frequency, Neuropsychopharmacology, 2014.

The dream talks about things that were already in the air

The continuity hypothesis, tested by Michael Schredl and Friedrich Hofmann in 2003, shows that dreams follow whatever fills waking life. If you have been worried about your father's health, it is natural to dream about him in a hospital. If he falls ill weeks later, the dream looks like a warning, but the worry came first because you were already noticing signs: how tired he was, a medical test that kept being postponed, a remark on the phone.

In this sense, the dream can even "get it right" without predicting anything: at night, it puts together pieces the mind already had during the day. For traffic scenes, see dreaming about an accident.

Source: Schredl and Hofmann, Continuity between waking activities and dream activities, Consciousness and Cognition, 2003.

See also: Thursday night dreams and Children's nightmares by age and how to comfort your child.

Memory changes the dream after the fact

Baruch Fischhoff published a classic study in 1975 with a title that sums it all up: hindsight is not the same as foresight. Once people know how something turned out, they start to think the outcome was predictable from the start. This is called hindsight bias.

With dreams, the effect is strong. Last week's dream was vague: a road, a noise, someone crying. When the news arrives, memory fills the gaps with details from the real event, and the dream becomes sharper in memory than it was that night. It is the same mechanism that explains why so many people remember the same thing wrong.

Source: Fischhoff, Hindsight is not equal to foresight, 1975 (reprinted 2003).

Freud, Jung and faith before the dream that comes true

In Freud's psychoanalysis. Reviewing what had been written before him, Freud describes belief in the power of dreams to foretell the future as a conflict between an almost unshakable skepticism and claims stubbornly repeated. He bets that many cases would find an explanation in psychology and points out that, since so much of a dream is lost, the memory of what remains may be distorted. He also tells a story from his own family: an old peasant woman predicted to his mother that her son would be a great man. For Freud, prophecies like that must be very common, because hopeful mothers are everywhere and those who prophesy have nothing to lose.

In Jung's psychology. Jung accepted that dreams sometimes anticipate situations, but he explained it another way: many crises have a long unconscious preparation, and the dream records the path before the person notices it while awake. For him, this did not need to be a miracle or fortune-telling.

In symbols and in faith. In Christian tradition, there are dreams that announce the future, like Pharaoh's in Genesis. But Deuteronomy, in chapter 13, warns that not even a sign that comes true is enough to prove the person who announced it right. That is why many believers treat a dream that "hit" with prayer and prudence, without turning it into a rule. Read more in dreams in the Bible.

Bringing the two readings together. Faith may see care in the dream; science sees worry, coincidence and memory. In both, the way forward is to act calmly.

Sources: Freud, Die Traumdeutung, 1900; Jung (ed.), Man and His Symbols; The Bible (Genesis 37, 40 and 41; Daniel 2, 4 and 7; Matthew 1 and 2).

How to test your own dreams honestly

• Write it down before, not after: record the dream as soon as you wake up, with the date. Only what was recorded before the event counts for comparison.
• Count the misses too: mark which dreams did not come true. After a few months, the proportion often surprises people.
• Ask what you already knew: when a dream seems to "hit," check whether there were earlier signs, even small ones.
• Do not make decisions based on the dream alone: canceling a trip, ending a relationship or acting because of a dream should go through a conversation with someone you trust. If you have symptoms, see a doctor, with or without a dream.

If you want to get started, see why we forget dreams and how to remember more.

When fear of the dream calls for help

If "warning" dreams leave you afraid to sleep, repeat every week or show up after a loss, talk to a doctor or psychologist. Frequent nightmares can be treated; see how to have fewer nightmares. If you are in intense distress, reach out: in the US, you can call or text 988 (Suicide & Crisis Lifeline), free and available 24 hours a day. See what dream meanings look like according to science and culture.

Source: Morgenthaler and colleagues, Journal of Clinical Sleep Medicine, 2018.