Roughly one in every 250 has never remembered a single dream

We dream for around two hours each night, on average

Every night we lie down to rest, we spend about two hours traveling through seemingly real experiences as dreams bubble up from our subconscious during various phases of sleep. Despite the ubiquity of the experience, where dreams come from—and what their purpose is—remains largely unanswered.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Why don’t you remember all your dreams?

Despite being a near-nightly occurrence, we remember very few of our dreams. Researchers believe reduced activity in regions where memories are stored, a different neurochemical environment during sleep, and rapid transition during waking contribute to this phenomenon.

How dreams affect your memory

In 1999, scientists conducted a study in which participants were asked to recall images flashed before them for milliseconds. They found that participants who slept before recalling the information performed better than those who had been asked to recall the same information that same day. This was some of the earliest convincing evidence of how crucial sleep is for learning and memory, findings that current research continues to strengthen.

Modern media exposure may impact whether people dream in color or black and white

A 1942 study found that 70.7% of college sophomores rarely saw colors in their dreams, while a similar survey in 2003 showed that only 20% reported the same. The prevalence of color television and films may make color dreams or the recollection of color features easier to remember.

Your brain moves through four distinct sleep stages every night

Each stage plays a key role in memory, repair, restoration, and other key biological functions. The full cycle generally proceeds from light sleep and deep rest into vivid REM dreaming, which repeats between three and five times nightly.

Dreams largely occur during REM sleep (but not entirely)

Modern imaging tools have enabled scientists to carry out in-depth studies of brain activity during sleep. Researchers know dreams arise largely during REM, blending emotion-driven visual imagery, memory consolidation, and weak associations to help us make sense of experiences, regulate emotions, and prepare for future situations.

Why do dreamers twitch?

This thought-provoking piece highlights newer research suggesting sleep twitches may not be random dream leftovers, but instead a crucial way our brains map and understand our bodies. From sleeping rat pups to dreaming octopi, this biological mapping system appears universal across animal species.

The hippocampus plays a central role in dreaming

It's theorized that the hippocampus—a brain structure involved with memory formation and the simulation of imagined and novel scenarios using those memories—plays a major role in dreaming. Studies of people with damaged hippocampi show that they still dream, but their dreams lack the richness of detail described by others.

About 10%-15% of people experience chronic insomnia

How often would you say you struggle to stay or fall asleep? If it's more than three times per week (and has been going on for at least one month), then you might have one of the most common sleep disorders: insomnia.

The benefits of lucid dreaming

Lucid dreams happen when the dreamer knows they've stepped out of the bounds of waking life. Studies show it can help dreamers cultivate creativity, process grief, and work through trauma. A 2021 study found that 85% of participants with PTSD no longer qualified for the diagnosis after a week of trauma-informed lucid dreaming in which they intentionally witnessed (and therefore integrated) recurring nightmares or changed the outcome completely.

Four in 10 CPR patients report consciousness not captured by standard measures

A recent study found people revived by CPR after cardiac arrest reported they experienced some amount of consciousness during clinical death, suggesting our brains are capable of thought and memory for significantly longer after death than previously thought.

For most of recorded history dreams were considered divine in origin

The first venture into modern dream interpretation may have been when ancient Greek philosopher Heracleitus proposed dreams were created within the mind. In the late 1800s, the rise of psychoanalysis theorized that dreams content revealed truths about one's psyche, while the invention of the electroencephalogram linked dreams to brain functions.

Photographic memory isn’t real, but other rare memory types do exist

While 2% of children can recall sensory experiences with extreme detail (eidetic memory) and some adults can remember life events or dates with high accuracy (hyperthymesia), there is no scientific evidence for the flawless recall popularized in fiction. Most memory feats instead rely on training and memorization techniques.

Nightmares are unpredictable, but are linked to stress, anxiety, trauma, and more

Nightmare comes from the terms "night" and "mare," an Old English word for evil, suffocating spirits. Nightmares are parasomnias, meaning they are undesirable events experienced during sleep, and may stem from building tensions in one's unconscious.

The average American likely doesn’t notice how many ads they’re targets of per day

The average American is targeted with roughly 5,000 ads each day—but the conscious mind likely isn’t capable of recalling the majority of those. Even still, many consumers have reported ad fatigue due to the near-constant onslaught of ads.

'Those who dream by day are cognizant of many things which escape those who dream only by night.'

- Edgar Allan Poe (1809-1849) in "Elenora"

How to remember everything

On average, people can remember seven different things using their working memory. To better retain all the things we need to remember, Tiago Forte developed the Second Brain method: a simple approach for immediately capturing, organizing, and storing the myriad tasks, learnings, and resources we collect throughout the day.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Obsessing over sleep metrics leads to worse sleep quality

Over one-third of Americans have used wearable technology to track their sleep, and the anxiety over having perfect sleep data, or orthosomnia, has made getting a good night's sleep more difficult. Experts agree that most devices cannot correctly assess sleep details, making the data unreliable.

Some animals seem to live well on little sleep

African bush elephants typically sleep for about 2 hours per 24-hour day, coming in well under a human's recommended seven-hour minimum. Other animals also appear to skimp on sleep, by human standards, without the consequences humans associate with being sleep deprived. This academic article details the sleeping habits of animals that appear to thrive on fewer than 40 winks and explores whether their sleep processes are just built different.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

Dreaming under the Nazi Regime

Days after Hitler seized power, a man told psychoanalyst Charlotte Beradt that he had dreamed of being forced to raise his arm in a Nazi salute ("It took me half an hour to get my arm up, inch by inch"). Beradt recorded this dream and many others so they "might one day serve as evidence." This is an English translation of her work, "The Third Reich of Dreams."

Someone suffers from a stroke every 40 seconds

Every 40 seconds, someone in the US experiences a stroke—and every minute without treatment destroys millions of brain cells. This explainer breaks down the two main types of strokes, their risk factors, and how early detection could change outcomes in the future.

Humans accurately detect their goose bumps only about one-third of the time

Though people do experience goose bumps frequently, goose bump research suggests that humans think they’re experiencing goose bumps in response to emotional cues more often than they truly are.

Roughly 15 of every 1,000 people in the US have smell disorders

Anosmia is a lack of a sense of smell. It can be present at birth, related to diseases including Parkinson's, Alzheimer's, and COVID-19, or have unknown causes.

To get that song out of your head, try distracting yourself or playing a new song

Around 90% of people experience getting a snippet of a song stuck in their head, also known as an earworm. Researchers think they are linked to memory, repetition, and inner rehearsal. Before written language, music was used alongside rhyming in many cultures to help people preserve oral histories.

Most people don’t keep their New Year’s resolutions

Studies suggest that only 9% of Americans who make resolutions keep them; 23% quit by the end of the first week of the new year, and 43% quit by the end of January.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

11 people died from firework injuries in the US in 2024.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

Frank Lloyd Wright's houses are historically hard to sell because they're old, subject to local landmark commissions, and often unfashionable

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

One of the most famous portraits ever taken is 'Afghan Girl' (1984) by Steve McCurry, yet the subject Sharbat Gula went much of her life without being identified or benefitting from the image's success.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions