As I've said before, it is hard to know when things started to go wrong. One undeniable change was what happened one Christmas. As with many families, Christmas at our house was no idyll; there were tensions and disagreements that didn't always remain beneath the surface of good will and cheerfulness. My mother wanted to cook Christmas lunch, since that was traditional, and it allowed time to clear up before the end of the day. I wanted to have the big traditional meal late, at dinner time, when the day was a little cooler, and the wine wouldn't wipe out the afternoon. Greg wanted a prawn and salad Christmas. He wanted no mince pies, I wanted hundreds. Some of us wanted to buy presents for everyone, others thought it was silly as we had all developed quite particular tastes of our own and didn't need any more possessions. Some went to church, others didn't. Amidst all this tension, mum couldn't keep all the balls in the air. She was trying to bring the turkey, the Yorkshire pudding, the Christmas pudding, the mince pies, the custard and all the rest of the usual foods to the table at the right time, the right temperature and looking just right. Nothing particular went wrong, but her ability to cope with a situation she had handled perfectly year after year was just no longer there. She was almost in tears. Greg's wife Regan decided that, come next Christmas and forever more, she would look after the preparations.

Some time after that year mum was due to fly to Queensland to stay with Rachel for a couple of weeks. On the eve of her departure she got so worked up about having to get on the aeroplane that my dad called to say that he didn't think mum could make it. I had to call Rachel to break the news to her. The trip never did take place. Having lost the ability to organise a large family gathering, mum had now lost the ability to travel.

Months passed, then I got a call from dad to say that there had been a fire and he needed a bit of help. Mum had intended to cook chips the previous evening. She had started to heat the oil and then gone into the lounge to watch television. The oil caught fire and smoke started to fill the house. The smoke alarm started screeching but they simply sat and wondered who was making that irritating noise. The marks on the walls showed that smoke accumulated against the ceiling, creeping ever lower as mum and dad watched the television. It must nearly have been obscuring their view of the screen by the time they realised something was wrong. They both went into the kitchen and saw flames reaching almost to the ceiling. They forgot about the fire extinguisher. Dad opened the back door and mum carried the burning pan out, then threw the oil onto the grass. She got burns to her forehead doing this. The wall above the cooker was burnt, but otherwise there was only smoke damage. They were extremely lucky. Greg bought them a fire blanket, changed the smoke alarm and provided a chip-cooker for future fry-ups.

Since then, mum's abilities in the kitchen have slowly disappeared. Twice she destroyed electric kettles by putting them on gas burners. I've now turned the gas off. Once, Rachel was there only just in time to stop mum and dad eating catfood on toast. Just recently, mum finally stopped being able to make a cup of tea. She gets margarine out of the fridge instead of milk. Just this week she poured the old tea from the tea-pot back into the kettle to heat it. She doesn't recognise boxes of tea-bags.

If I turned up at the house when dad was out doing a bit of shopping, I would often find my mother in a state of rage. 'He's been gone five days, and didn't say anything about where he was going, or when he is coming back,' she'd say. This would be less than an hour after dad had left.

Not long ago I was washing dishes at the sink, and mum joined me to dry them. She was trying to do this with a plastic bag. I said, 'oh, I think we've got a better one for that job,' and found a dishcloth for her. She accepted it quite gratefully.

She has started concealing things in her bedroom. Her handbag has a variety of hiding places, which she then forgets. When she cannot find it later she often starts to talk about it being snatched from her, remembering an incident that took place nearly twenty years ago. She is usually amazed, and always grateful when I find it for her. Other things that frequently turn up in her bedroom are old pieces of chocolate and other food, letters (usually addressed to my dad), and sometimes coins.