# Did I lock the door?

> If you can't remember locking the door, you most likely did it on autopilot, which leaves a weak memory that blends with every other day you locked it. Check now with a neighbor, a smart lock app or a trip back, then build a leaving routine that ends with a deliberate, noticed lock so the memory sticks.

You're at the bus stop, or three exits down the highway, and a small cold thought arrives: did I lock the front door? You can picture your hand on the key. You just can't tell if that picture is from this morning or from last Thursday.

This is one of the most common memory gaps there is, and it says almost nothing about how careful you are. The cause is simple, the question can usually be settled in a minute, and a couple of small habits make the doubt show up far less often.

## Why you can't remember

Locking the front door is a motor habit. Your hands do it while your head is on the meeting, the kids, or whether you packed lunch. Because your attention was somewhere else, your brain never stores a clear, detailed memory of the moment. There's a trace, but it's faint.

The second problem is that every lock looks the same. You've turned that key hundreds of times, in the same spot, with the same click. When you try to recall today's lock, your brain pulls up a generic image built from all of them. Psychologists call this a source-monitoring error: you remember the event, but not which day it belongs to.

Going back to check doesn't fix this, and it can make it worse. Studies on repeated checking (van den Hout and Kindt, 2003) found that the more people checked something, the less confident they felt about their memory of it. Each check adds another near-identical memory to the pile, so today's becomes even harder to pick out.

## How to check right now

- **Ask someone nearby.** A housemate, neighbor or building manager can try the handle in thirty seconds. It's a small favor, and most people are happy to do it once.
- **Open your smart lock or camera app.** If you have a connected lock or a doorbell camera, its app will show the lock status or recent footage of you leaving. This is the fastest way to know for sure.
- **Walk through the last minute before you left.** Replay it in order: shoes, bag, keys, door. Details that are specific to today, like the coffee cup in your other hand or the rain on the step, are a better sign the memory is real than the general feeling of locking.
- **Decide whether going back is worth it.** If you're five minutes away and genuinely can't tell, going back once is reasonable. If you've already checked once today, a second trip tends to feed the doubt more than it settles it.

## How to stop rechecking

- **Say it out loud as you lock.** "Front door locked, Monday." Speaking forces a moment of attention and adds a detail, the day, that separates today's memory from all the others.
- **Touch and name.** After you turn the key, push on the door and say what you're doing. The physical push gives your brain a second, distinct signal to store.
- **Make locking the last step of a fixed routine.** Keys, phone, wallet, lights, then lock, every time, in the same order. When locking is always the final step, finishing the routine is good evidence that you did it.
- **Consider a smart lock with auto-lock.** Many smart locks relock themselves after a set time and show their status on your phone. They cost more than a deadbolt and need batteries, but for chronic doubters they remove the question entirely.
- **Keep a timestamped record.** One Loop lets you snap a quick photo of the locked door as you leave. The photo is stamped with the time and stays in the app, so when the doubt comes, you open it and see this morning's lock instead of guessing.

## Set it up in One Loop

Loop name: Front door. Confirm with: Camera. Reminder: No reminder. A photo of the locked deadbolt is hard to argue with. You take it on the way out, and it's there with a timestamp when you start wondering at the bus stop.

## Questions people ask

### Is it normal to forget if I locked the door?

Yes. Locking up is so automatic that most people don't form a clear memory of it, and the days blur together. It happens to careful people all the time.

### Why do I keep checking the door over and over?

Each check creates another similar memory, which makes it harder to trust any one of them. If checking takes up a lot of your time or causes real distress, it's worth talking to a professional; the IOCDF (iocdf.org) has good resources on compulsive checking.

### Do smart locks lock automatically?

Many do. Most popular smart locks offer an auto-lock setting that relocks the door after a delay you choose, and their apps show whether the door is locked.

### How can I remember locking the door?

Add attention and a unique detail at the moment you lock. Saying it out loud, naming the day, or taking a quick photo all give your memory something specific to hold onto.

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Source: https://getoneloop.app/did-i/lock-the-door
One Loop for iPhone: https://apps.apple.com/us/app/one-loop-proof-you-did-it/id6802970270