I never thought I'd have anything in common with an engineer. Must be the attraction of opposites, says Annabelle Thorpe
It is a Sunday morning and all is right with the world. Barely awake, I see the next few hours shimmy in front of my slightly hungover eyes: more sleep, then breakfast, huge and unhealthy, a read of the papers, a quick doze, a call to my mum, and a blissful return to sleep. Up in time for EastEnders. Perfect.

An hour later, things are not going as I had imagined. The stereo is on, loudly. There is banging and crashing in the kitchen, and the smell of burnt scrambled egg and strong Sunday coffee that wafts down the hall can mean only one thing. Rob, my partner, is up. The idyll is over. The plan for the morning fades before my eyes.

We're very different, Rob and I. On the surface, at least, we are living proof of that old "opposites attract" adage. He says potayto, I say potarto. He says tomayto I say tomarto. He says ergonomics, I say - what? I say Ben Okri, he says who?

Life likes to trip you up. After 24 years of surrounding myself with fellow arty types, wafting around quoting Lawrence and turning down Jean Claude van Damme in favour of Jean de Florette, I have fallen in love with a man who did maths and physics at A-level and a degree in engineering. In three years at uni I never befriended a single engineer - they were best off left in the boffin encampment on the edge of campus. After all, they were obviously on the outskirts for a reason.

This is not how I imagined things would be. I had always envisaged staying up all night with my partner, discussing underlying themes in The Tempest or arguing about Austen's sexuality. Though I have to admit that when I did - albeit briefly - get involved with a fellow arty type it was a disaster. My boyfriend's ego couldn't deal with my disagreeing on matters literary, and the evenings inevitably ended with either an argument, or my falling asleep.

According to Roger McGhee, a psychologist, competitiveness can be a feature of relationships where partners are alike. "If both partners have similar areas of expertise there can be problems. Both think themselves right and this can often lead to disagreements and resentment."

This is certainly not a problem we face. Most of Rob's interests are so far removed from mine that I don't have an opinion on any of them. Six months ago I couldn't spell ergonomics, let alone define it. I'd never heard of Jungian philosophy or homeopathic medicine. (Yes, he is an engineer, honest.) Rob's way of thinking is so different from mine that it's made me see other ways to took at life. Until I met him I'd always been terribly unaware of my surroundings - if I'd been in a bank when a robbery took place, I'd probably have held the door open for them to leave. Rob, being interested in design and how the world works, has changed all that.

"Being with someone whose interests are different means you learn from them," says Roger McGhee. "If you are too similar, you may use them as some kind of indicator of your own quality and competence. This is dangerous - this kind of personal comparison belongs at work, not in a relationship."

It does seem easier to keep a sense of individuality when you are very different from your partner, and it also gives you the pleasure of opening up your life and showing them around. Rob loves explaining the theory behind things, from nature to aeroplanes, and I like to listen. I'm still unconvinced as to why aeroplanes don't fall out of the sky, and simply don't believe that clouds contain six million gallons of water (or something like that) but it's made me think.

So the attraction of opposites is generally a good thing, it seems. Wrong. Roger McGhee believes that in the long run it is much harder for very different partners to have a successful relationship. "Two people who share similar attitudes to life have a much greater chance of success than two who are poles apart. Nearly all the research that has been done has proved that the idea of opposites attracting is simply a myth. What does work is when superficial interests are different, but deeper attitudes and motivations are similar."

I suppose that underneath the English Patient (me) or Star Wars (Rob) debates, we do both want the same things from life. But our temperaments are very different. I can be quite volatile, while Rob has an aura of calm around him like a Ready Brek glow. He'll be trying to understand why I've flown off the handle again, and I'll get increasingly irritated by his ability to stay in control. It does annoy me, but it calms me down, and, most important, shuts me up. At 9am on a Sunday morning with the stereo blaring, however, it can be difficult to bear that in mind.

"It's a difficult choice," says Roger McGhee. "Do you go for the comfortable, safe option, or try something different and more challenging? If you spend your life with someone similar to you, often your prejudices are never questioned and your aspirations never heightened. Being with someone different is far from easy, but it stretches and changes you."

He's not wrong. There are times when it seems that there are no differences between us, curled up on the sofa ploughing through piles of hot buttered toast (a shared passion) watching The Holiday Programme (another shared passion). But as the credits roll, reality dawns. Peace is shattered. EastEnders is on BBC 1, Equinox on Channel 4. The debate begins.