I know how she feels. Not that I have voices in my head – but I talk to myself all the time. And not just for perfectly understandable reasons like learning new things. We have a new system on the computers at work and to help me master it I've been talking myself through each step every time I have to process something. Fine for me – hell for the poor colleagues who have to sit next to me as I witter away.

I've always talked to myself – most people do, don't they? But I didn't really start to do it out loud until I was learning to drive. An instructor thought it would be helpful if I talked myself through everything I had to remember. Well, he thought it would be easier on his gearbox, that's for sure.

So he suggested that I talk out loud to myself and detail every stage as I went through it, rather than forget, grind my teeth as well as his gears and then have us both spend the next half hour cursing. And it's a habit that's stuck. The talking to myself, I mean. Well, the cursing as well, truth be told.

Shops up and down the land have CCTV footage of me gibbering away to myself. There must be security guards all over the place who have zeroed in on the loony woman acting suspiciously. I'm at my worst when I'm even slightly undecided.

Added to my generally erratic behaviour – I pick something up, put it down, walk a few steps away, then turn around and pick it up again – I talk to myself all the way through it.

"Ooh, that's nice. It would go wonderfully with that green shirt. No. No. Don't need it. No, don't need it at all. Just leave it. You have a hundred of them at home already. You don't need another one. But… it really would go beautifully with that green top." Etc.

I talk to myself all the way around the supermarket. Not just in an effort to remember a shopping list, but a whole stream of consciousness. One item on my list last week fired a wee synapse that sent me off at an unfathomable tangent until I found myself in the middle of cereals and condiments babbling on about swimsuits and verruca protection.

Of course, I don't just talk to myself. That would be stupid. I talk to other people as well. Well, I pretend to talk to other people. I'm not really making this any better, am I? For example, I rehearse what I'm going to say before an important meeting – and what the other person is going to say as well. I prepare for what I know is going to end up as an argument by fighting my side first.

Which comes as a bit of a surprise to people standing at the bus stop of a morning as I stride past them, excitedly muttering and gesticulating. Although, strangely, it doesn't always work out as I imagine it. Can't think why. When I've rehearsed the argument beforehand, I've always won.

But that's because I'm always right and eventually my (imaginary) opponent sees sense and capitulates. And, of course, I always get the last word.