I remember my last day at GMTV. I was there for 12 years. It was 15 all in all, but 12 sitting and presenting it. I thought I would cry all the way through the final show, but it was just a huge sense of relief! I remember all my colleagues ended up sitting on the sofa with me and there were amazing tributes from the prime minister, Posh and Becks, Take That, lots of people I'd built up relationships with over the years. I'll never forget it.

We take it for granted, but memory is fundamental to everything you do. If you want to do a quick calculation you remember your timetables and the things you are taught at school. As soon as you start losing your memory your whole life goes into meltdown.

When my mother started having trouble with her memory it was difficult because she was only in her 50s. At the time we just thought she was being eccentric. She had always been funny, always saying the wrong thing at the wrong time and we would think 'I can't believe she said that!'

But this was an exaggerated form. She started crying a lot. She used to love coming to stay with me in London but I remember her getting off the coach one day and she was crying. I asked her what was wrong and she couldn't tell me. She couldn't remember which bag was hers and even though I pointed it out for her, it didn't register for her. I remember thinking then that something wasn't right.

This sort of thing went on for years but because I didn't live on a day-to-day basis with her, I would phone her and think she was fine. Although when I think back, and you do a lot of thinking back with Alzheimer's, I think, "God, I wish I'd known". She was a very warm, sunny person and she just started getting colder and more distant.

My mum died in 2006 and at this time my dad had been behaving really oddly. One day we left my dad with a solicitor and about 10 minutes later the solicitor phoned me and said my dad couldn't make a will because he didn't know his sons' names or his own address. I told the solicitor that he had just lost my mum, that he was depressed and that a lot of people can't remember things when they are grief-stricken.

Again, stupidly, my brothers and I couldn't believe it could be true that he had Alzheimer's as well. He was only in his 60s then. My dad was never one for phoning us but one night he phoned me and he was crying and I had never heard my dad cry, he said, "I've got letters I don't understand, I've got bills and I don't know what they are".

My dad never told us he loved us as children, we knew he did, but he never really said "I love you". When he had Alzheimer's he told me all the time, I was overwhelmed by it. He used to hug me all the time and we would dance around in his flat - all things that Dad would never have done.

We thought dementia was just old people saying funny things and forgetting things, we didn't realise it was something more menacing. If only my parents had got an early diagnosis, I would have been able to plan things. We would have looked around and made a plan that everyone was happy with, instead of doing everything in a big rush and everything being chaotic and catastrophic with one emergency after another. We would have been able to prevent things happening like my mum setting the kitchen on fire. When you have an early diagnosis there are things you can do.

www.nhs.uk/dementia