I have a problem with locking my front door when I go out.

The problem is not that I forget to do it, in general. I hardly ever forget. But I did forget once and leave it wide open (fortunately with no resulting burglary), and I've been hugely paranoid about forgetting ever since, and that's the problem.

You see, going out of my front door is something I do quite a lot, and it's very similar every time I do it. So if I get out of sight of my front door and then think ‘wait a minute, did I lock it?’, I can't remember. Because any clear memory I have of locking the door might just as easily be from yesterday as from today, so even if I can bring such a memory to mind it doesn't help me be confident that I've locked the door this time.

It's not so bad if I'm only one minute away from home when I think this. Then I can turn round and go back to check, and because that's not a usual part of my routine I'll be able to remember that I checked for the rest of the day and that will stop me from worrying. But if I think it when I'm most of the way to work, or worse still half way down the motorway to Reading to to visit my dad, then it's not really practical to go back and check, and I have no way to prevent myself from worrying my head off for hours or (in the latter case) days.

I get it particularly badly when my morning routine is in some way unusual, because that's when I think I'm most likely to make mistakes. Today was particularly bad, because I had to brush the snow off the car, and half way through doing that I noticed the door was still wide open and thought ‘better remember to lock it once I finish clearing snow’. Twenty minutes later I realised that I had a vivid memory of having thought that, but couldn't call to mind any memory of actually following through on it. I worried about it most of the way to work, and then finally managed to remember that when I was locking the door I noticed a piece of litter someone had apparently discarded in my driveway the previous night. Bless you, litterbug; if it wasn't for you I might actually have had to turn round and go home again to make my brain stop yammering.

I have not yet succumbed to the obvious geek solution of setting up a webcam inside my house pointing at the door. (I only really need to check that it's shut, because I am confident of my procedure for making sure I never shut it without also locking it.) I may yet resort to this, since most of the places I go are net-connected so I could easily check the webcam once I arrive. But it seems like an admission of defeat; this is a problem in my mind alone and I surely ought to be able to find ways to solve it in my mind.

My best strategy so far is to try to make locking the door a memorable event. I generally do this by coming up with some faintly amusing ditty, or a mangled quotation in which I substitute some words about locking or doors. For example, ‘I locked the door and the door won’. Or ‘It was the Door of the Third Age of Mankind’. Or singing ‘now I have locked the dooooor’ to the Blake's 7 theme tune. Or even just chanting something inane like ‘I've locked the door, I've locked the door, dee-doodly-doo, I've locked the door’. Whatever. Prose, rhyme, tune, it doesn't matter; as long as it's different from yesterday's one and sticks in my mind well enough that I can remember it when I suddenly panic two hours later, it's good enough.

But sometimes, of course, I forget to do that, and I just lock the door and charge off to wherever I'm going, and then I'm back to the same problem again. As this morning.

I can't think of any other way to make myself more reliable at remembering I don't have to worry. It feels particularly silly that I'm not even trying to increase my reliability at actually locking the door; that's absolutely fine as it is. It's just that I worry about forgetting in huge disproportion to the chance of me actually forgetting.

Perhaps I should just give in and buy the wretched webcam. :-/