Mrs Redgrave taught English at Plymouth's Public Secondary School for Girls. She was a fabulously exotic creature amid the stern, strict atmosphere of a girls' grammar school in the late 1950s.
She was married to the brother of Michael Redgrave, the famous actor, and she had red hair that she wore in sausages all over her head. She would also wear the most spectacular shoes - fabulous, colourful, three-inch stilettos. If any of us got bored with English, we'd say: "Oh Mrs Redgrave, we love your shoes. Where did you get them from?" Then she would go pink in the face and stumble over her words.
She was such a gentle soul; I don't think she should have been a teacher. She would have been better suited to a quiet life as a research assistant in a university.
We girls were merciless, although never unkind. We teased her because she was so easily distracted, but it was with affection. We absolutely loved her. She was such an antidote to the rest of the teachers with their earnest expressions and flat shoes.
Mrs Redgrave loved the English language and she was almost on an ethereal plane when she was reading poetry to us spotty 15-year-olds. She was so enthusiastic - she had the ability to put across the beauty of the English language.
It was a joy to be taught by her. She introduced me to English literature and the magic of the written word on the page. She brought plays and novels alive for me. I read about 50 books a year now and that's no exaggeration. I studied A Midsummer Night's Dream with her and I adore it to this day. It's the same with Pride and Prejudice, which I chose as my book when I was on Radio 4's Desert Island Discs.
And because she was such an engaging teacher, when we did knuckle down to our work, we all got brilliant results.
I got 11 O-levels and I was one term away from completing my A-levels when I left school for a job on the local newspaper. I'd wanted to be a journalist, specifically a photojournalist, ever since I was 9 and my dad bought me a Brownie box camera.
My parents were supportive of everything I did. But when I left in the Easter holidays of my final year, my name was mud at school. I was reasonably academic and the teachers had hoped I'd go on to university. I remember winning the school science prize (although I can't recall what for) and my physics teacher thought I might go off and become a scientist.
I didn't keep in touch with Mrs Redgrave but I'll always remember her. She helped me to grow as a person; to grow up and stop being silly. She is an example of how inspirational teachers can really make a difference to young people. Not just to their academic achievements but to how they develop as adults.
Now I'm working with the Alzheimer's Society to help schoolchildren become more aware of dementia. Very often the success of our dementia programme is down to inspirational teachers who say, "I get this."
A teacher like that can make such a difference because they instil in children knowledge that they take into their maturity. With Mrs Redgrave, it didn't go in one ear and out the other. It stuck, which is why we're talking about her 50 years on. You can't underestimate that.
Angela Rippon was talking to Kate Bohdanowicz. Rippon is co-chair of the prime minister's Dementia Friendly Communities Champion Group, which works to raise awareness and understanding of dementia. Resources on dementia from the Health and Social Care Partnership are available on the TES website at bit.lyDementiaResource
Born 12 October 1944, Plymouth
Education St George's Primary, Stonehouse, Plymouth; Public Secondary School for Girls, Plymouth
Career Journalist, newsreader and television presenter