Brain Matters · Memory
Most memory slips are normal. Here is how to tell everyday forgetting from changes worth a doctor's visit, and when confusion needs help right away.
The short answer
Most forgetting is normal. Stress, poor sleep and divided attention cause most everyday slips, like losing a name and remembering it later. See a doctor when memory problems keep getting worse, when other people notice them, or when they get in the way of daily life.
- Forgetting a name or why you walked into a room is common at any age.
- Getting lost on a familiar route or struggling with routine tasks is worth a doctor's visit.
- Confusion that comes on over hours or days is a medical emergency. Call 911.
- Some causes of memory problems, like low vitamin B12 or an underactive thyroid, can be treated.
We all forget things. An appointment, a name, the reason you walked into a room. Most of the time these lapses are harmless. But when forgetting happens more often, or starts to get in the way of daily life, a harder question comes up: is this normal, or is it a sign of something more?
Is it normal to forget things?
Yes. Everyone forgets, and some kinds of forgetting become more common with age. Harvard Health describes several normal memory problems, including fading details over time, slips caused by not paying attention, and "blocking," when a word or name is on the tip of your tongue but won't come out.[1]
Normal aging tends to slow how fast you recall things and how fast you learn new ones. It does not usually erase what you know. Vocabulary, skills you have practised for years, and important memories tend to hold up, even when recall takes longer.
How can you tell normal forgetting from a memory problem?
Look at the pattern, not a single slip. Normal forgetting comes and goes, and the memory often returns later. A memory problem keeps happening, tends to get worse and starts to affect everyday tasks. The Alzheimer Society of Canada lists memory changes that affect daily life, trouble with familiar tasks, getting lost in familiar places and misplacing things often among its warning signs of dementia.[2]
| Usually normal | Worth raising with a doctor |
|---|---|
| Forgetting a name, then remembering it later | Forgetting recent conversations or events, even with reminders |
| Misplacing your keys now and then | Misplacing things often and not being able to retrace your steps |
| Missing a bill once during a busy month | Struggling with bills, cooking or other tasks that used to be routine |
| Searching for the right word | Losing words often, or calling common objects "that thing" |
| Forgetting why you walked into a room | Getting lost on a route you know well |
| Feeling foggy after a poor night's sleep | Changes in mood, judgment or interest in usual activities |
When should you see a doctor about forgetfulness?
See a doctor when memory changes keep happening, get worse over time or affect daily life. The same goes if family or friends notice a change before you do. You don't need to meet a checklist first. If something worries you, it is reasonable to ask.
A visit usually starts with a conversation about what has changed and when. Your doctor may use a short memory and thinking test, such as the Montreal Cognitive Assessment (MoCA), and order blood tests. Some causes of memory problems can be treated. A lack of vitamin B12 and an underactive thyroid can both affect memory and concentration.[5] Your doctor will also look at your medicines, your mood and your sleep.
It helps to bring notes. Write down examples of what you or your family have noticed, when they started, and a list of everything you take, including vitamins.
Worried about a parent?
Starting the conversation can be the hardest part. Our guide on how to talk to your parent about cognitive changes has practical steps.
When is confusion an emergency?
Confusion that comes on suddenly, over hours or days, needs medical help right away. In Canada, call 911 or go to the nearest emergency department. Sudden confusion, also called delirium, is different from the slow changes of dementia. The McMaster Optimal Aging Portal describes delirium as a medical emergency that starts quickly and can come and go.[4]
Sudden confusion can be caused by an infection, a stroke, low blood sugar, a head injury or some medicines, among other things.[3] Many of these need urgent treatment, so don't wait to see if it passes.
What causes everyday forgetting?
Most everyday forgetting comes from how information goes in, not from losing it for good. Your brain takes in a huge amount every day. It holds on to what you pay attention to, repeat or care about. Details that never get your full attention often fade before they are stored.
That is why forgetting is more common when you are stressed, tired or doing several things at once. If your attention is split, a memory may only form partly, so it is hard to find later.[1]
New information can also get in the way of old information. This is called interference. A new password can crowd out the old one. A new route to work can blur the one you used to take.[6]
For people in midlife, our article on forgetfulness in your 40s looks at how stress, sleep and busy lives affect memory at that age.
Why does the brain forget on purpose?
Scientists now think some forgetting is an active process, not just memories wearing out. A 2017 review in the journal Neuron describes several ways the brain clears out memories it no longer needs.[6]
Much of this work began in fruit flies and continued in rodents. It points to a few processes. The connections between brain cells can be loosened by changes inside the cell. New brain cells can reshape existing memory circuits in animals. And new learning can push older memories aside.[6] Whether new brain cells form throughout adult life in people is still debated, so the human picture is less clear.
Forgetting may help the brain stay flexible. If you held on to every detail, it could be harder to learn new things or update old ones. This kind of forgetting is different from the steady loss seen in dementia, which is caused by disease.
How is Baycrest studying memory changes?
Scientists at Baycrest study how memory works, and how it changes, using tools such as high-resolution brain scans (MRI). Part of this work looks at grey matter in the temporal lobes, brain areas that are important for memory and are affected by Alzheimer's disease. The aim is to find changes earlier, before they affect daily life.
We are working on advanced methods to improve the "pictures" we take of the structure and function of the temporal lobes. Similar to the upgrades that you see with a new phone camera, we are working on more precise, reliable ways to measure the grey matter volume in areas affected by Alzheimer's disease.
Dr. Rosanna Olsen, Senior Scientist, Baycrest Academy for Research and Education
How can you support your memory?
You can't stop forgetting, but you can help your brain hold on to what matters. These everyday habits are simple to try:
- Test yourself. Try to recall something instead of rereading it.
- Space it out. Go over new information a few times, with longer gaps between each review.
- Focus on one thing. Doing several things at once splits your attention.
- Sleep. Tired brains find it harder to focus and remember.
- Move. Regular activity is good for your brain. Our article on dance and brain health has ideas.
- Keep learning and stay social. New skills and time with people keep your mind busy.
- Write it down. Calendars, lists and phone reminders take the load off your memory.
These habits help with everyday slips. They don't replace a doctor's visit if your memory is changing in the ways described above.
Questions and answers about forgetting
Does frequent forgetting mean I have dementia?
Not on its own. Dementia involves memory and thinking changes that get worse over time and affect daily life, such as managing money or finding your way. Forgetting that comes and goes with stress, tiredness or a busy schedule is usually normal. If you are unsure, talk to your doctor.
Why do I know I've forgotten something?
Your brain can keep track of its own memory. That feeling of a gap, or of a word on the tip of your tongue, often means the memory is there but hard to reach right now. It often comes back later, when you stop trying.
Can too much information make you forget?
Yes. Your brain can only hold a small amount in mind at once, so trying to take in too much can mean some of it never gets stored. New information can also get in the way of older information that is similar, like an old and a new password.
Why do I forget what I just read?
Often because your attention drifted before the information was stored. Reading while tired, stressed or distracted makes this more likely. Pausing to sum up what you just read, in your own words, can help it stick.
Can memory problems be reversed?
Some can. Memory problems caused by a lack of vitamin B12 or an underactive thyroid can improve with treatment, and doctors also look at medicines, mood and sleep. That is one reason it is worth getting memory changes checked rather than waiting.
Sources
- Harvard Health Publishing. Forgetfulness: 7 types of normal memory problems. 2021.
- Alzheimer Society of Canada. 10 warning signs of dementia. Accessed 2026.
- NHS. Sudden confusion (delirium). 2025.
- McMaster Optimal Aging Portal. When confusion strikes quickly: Recognizing and preventing delirium. 2026.
- Alzheimer's Research UK. Other causes of memory and thinking problems. 2026.
- Davis RL, Zhong Y. The biology of forgetting: a perspective. Neuron. 2017.
Further reading
- Baycrest Foundation: Forgetfulness in your 40s: normal aging or early sign of dementia?
- Baycrest Foundation: How to talk to your parent about cognitive changes
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