You're halfway to work when the thought strikes: "Did I lock the front door?" You replay leaving the house in your mind. You remember grabbing your keys, maybe glancing at your phone. But the actual moment of turning the lock? Complete blank.
If this sounds familiar, you're far from alone. Research suggests that around 47% of UK adults have returned home specifically to check whether they locked the door at least once in the past year. It's one of the most common everyday worries—and understanding why it happens is the first step to solving it.
of UK adults have turned back to check if they locked the door
The Science of Autopilot
Locking your door is what psychologists call an "automatised" behaviour. You've done it thousands of times, so your brain runs the action on autopilot—much like brushing your teeth or tying your shoelaces.
This efficiency is usually helpful. Imagine having to consciously think through every step of locking a door: grip the handle, pull firmly, insert key, rotate clockwise, check resistance, remove key. We'd be exhausted before leaving the house.
The problem comes when we try to remember these automatic actions later. Because they require so little conscious attention, the brain often doesn't encode them as distinct memories. When you try to recall locking the door, there's simply nothing there—not because you didn't do it, but because your brain didn't consider it worth remembering.
Why Some Days Are Worse Than Others
You might notice the "did I lock the door?" worry strikes more often at certain times. That's not random. Several factors make us more likely to forget—or to doubt ourselves:
Stress and Cognitive Load
When your mind is full—work deadlines, family logistics, financial worries—there's less capacity available for routine tasks. The door gets locked on autopilot while your conscious mind is elsewhere, leaving no memory trace.
Disrupted Routines
Leaving at an unusual time, carrying extra bags, or being interrupted mid-routine all increase the chance of forgetting. Your autopilot relies on consistent patterns; variations throw it off.
Fatigue
Tiredness affects memory encoding. If you're exhausted when leaving the house, you're both more likely to forget and less likely to remember whether you forgot.
Age
While occasional forgetfulness is normal at any age, both memory and routine-following can decline as we get older. This doesn't mean serious cognitive problems—just that the door-locking worry becomes more common.
Key insight: Forgetting whether you locked the door isn't a sign of a bad memory. It's a quirk of how human brains process routine tasks. The action was likely performed—it just wasn't recorded.
The Real Cost of Door-Lock Doubt
This might seem like a minor annoyance, but the cumulative impact adds up:
- Time: Returning home to check costs 10-30 minutes depending on how far you've travelled
- Stress: The nagging uncertainty creates background anxiety that persists until resolved
- Lateness: Being late for work, appointments, or social events due to turning back
- Relationship tension: "Did you lock the door?" becoming a recurring household friction point
- Actual security risk: The ~25% of burglaries that occur through unlocked doors suggest the worry isn't entirely unfounded
Traditional Solutions (and Why They Often Fail)
Mental Checklists
Telling yourself to "pay attention when locking" works briefly, but the brain naturally returns to autopilot. The routine is too ingrained to override with willpower alone.
Physical Reminders
Some people try unusual actions—saying "locked" out loud, touching the door frame, or pausing to look at the key. These can help create memorable moments, but they require consistent execution and often fade over time.
Asking Family Members
"Did you lock the door?" shifts the uncertainty rather than resolving it. Now two people are unsure, or one person feels blamed.
Technology Solutions That Actually Work
The most effective solutions remove reliance on memory entirely. If you can verify the door's status without remembering the locking moment, the problem disappears.
Smart Locks
These replace your existing lock and show status via an app. They also allow remote locking—but this introduces new considerations around security and installation.
Lock Monitors
A lock monitor sits on your existing lock and reports whether it's locked or unlocked. You can check your phone from anywhere and see the current status, without needing to remember the moment of locking.
This approach has several advantages: no lock replacement required, no remote unlocking capability (which some see as a security risk), and typically lower cost than full smart lock systems.
Never Wonder Again
Locksure shows you whether your door is locked—right on your phone. No more turning back, no more uncertainty.
See How It Works →Practical Tips for Reducing Door-Lock Anxiety
Whether or not you use technology, these habits can help:
1. Create a Pause Point
After locking, take one second to consciously notice. Touch the locked door. Say "locked" quietly. This interrupts the autopilot just enough to create a memory.
2. Use Visual Cues
Place something by the door that you'll see only when leaving—a photo, a small sign. Use it as a trigger to consciously check the lock.
3. Reduce Morning Chaos
The more rushed and stressed your departure, the more likely you are to doubt yourself later. Preparing the night before creates calmer mornings and better memory encoding.
4. Accept Some Uncertainty
For occasional worriers, learning to tolerate the uncertainty ("I probably locked it, and I'm not turning back") can be freeing. The door is almost always locked.
When It's More Than Forgetting
For most people, door-lock worry is occasional and manageable. But if you find yourself checking multiple times before leaving, returning home frequently despite knowing you locked up, or experiencing significant distress around the issue, it may be worth exploring further.
Persistent, distressing checking behaviour can be associated with OCD or anxiety disorders. These are highly treatable conditions, and speaking with a GP is a good first step.
Read more: OCD and Lock Checking
The Bottom Line
Forgetting whether you locked the door is a universal human experience rooted in how our brains handle routine tasks. It's not a character flaw or a sign of declining mental function—it's just how memory works.
The good news: solutions exist. Whether through mindful habits, technology, or a combination of both, you can eliminate the "did I lock the door?" worry and reclaim that mental energy for things that actually matter.