Hannah Fry had always wanted to live her life by logic. She had a fight with her sister when she was a teenager. She used to say that she would take the pill if it was a complete pill.

She came up with a "mathematically informed" seating plan for her wedding, crunching factors such as age, political persuasion and predicted alcohol consumption to determine which guests should share a table.

Fry had always found numbers to bring clarity and comfort. She found the statistics working against her. The cancer had been confirmed by a routine test. She had two children at the time.

Fry said that the day of her diagnosis was a total out-of-body experience. If the cancer had spread, she would have to wait for the scans to show it. She had an essay written for the New Yorker.

Fry said he was sitting on his bed, drinking and crying. I don't know what the essay was about. Fry makes a face and laughs. The data can tell us a lot, but it can't tell us everything.

Fry has made her career out of demystifying figures and data so that they can be used in everyday life. She has interests that are broad and seemingly boundless.

Hannah Fry speaking in New York in 2018.

Hannah Fry speaking in New York in 2018. Photograph: Craig Barritt/Getty Images for Onward18

Fry has turned her interest in subjects as varied as the logistics of aviation and the science behind supermarket use-by dates into a passion.

The 20th series of The Curious Cases of Rutherford & Fry ended recently and will be back in the new year.

In her new show, Secret Wonders of the Modern World, she looks at inventions and innovations that we may not be aware of.

Fry greeted me from the back of the car, her hair still half-styled for the shoot. She thought no one was going to see her, so she left her pins in.

Fry considers herself a mathematician first and foremost, and a celebrity only if you like extremely niche math videos on the internet.

She admits that she doesn't know how to define her focus or preoccupation.

Fry has always been a big fan of knowledge. She was the daughter of an English father and an Irish mother who lived in Ware.

The phrase that I use is that I am intellectually promiscuous

Fry says that education was the number one priority. Every day of the summer holidays, her mother made her read a single page of a math textbook.

I wonder if the story is true because she tells it with so much joy. She said she was not happy about it. Her book, Hello World: How to be Human in the Age of the Machine, is dedicated to her mother, who never took "no" as an answer.

Fry obtained a PhD in fluid dynamics. She is a professor in the mathematics of cities.

She says Fry was never a natural mathematician because she was drawn to data as a means of telling stories. Fry gave a Ted Talk on "the mathematics of love" in the year 2014).

A promo shot of Fry’s BBC show Unvaccinated.

A promo shot of Fry’s BBC show Unvaccinated. Photograph: Jack Barnes/BBC/STV Studios

I would joke with my friends about how I was going to improve my dating strategy. The couple were set up by friends.

Fry still gets angry messages when she suggests that if you're still with your first partner, you should break up. The numbers will never take you so far. Fry says in the clip that there is no other way to do better.

The common thread is the unexpected intersection of data and humanity, especially where there might be real world applications.

She says that a book can hold as much interest as a potboiler. I want to share this incredibly juicy bit of gossip with everyone.

Fry has often acted as a go-between for the lay people who can't make sense of numbers and the experts who can't see beyond them. In the past two years, she has begun to realize that there are limits to playing.

Every decision is emotional according to her. It is not possible to put the data on either side of a scale and expect them to balance.

She has also had a learning curve due to her experience of cancer. Fry says that she may have understood the discussion better than most patients.

It doesn't matter if you have a PhD in mathematics or not, every single person is frightened about their future when they are in that situation.

Fry was uncertain. Her scans were ambiguous as to whether the cancer had spread or not, and whether it had, or hadn't, made a big difference.

Her chances of survival were greatly reduced if the cancer had only one lysoma, as her stage-one diagnosis immediately went to stage three.

Fry was told to go ahead and have a radical hysterectomy, removing not just her uterus and surrounding areas, but also all the scuplture in her body. She was told after her surgery that she had cancer and that it had already spread to her body's tissues. She says that she was in the room when it was over.

She was isolated in the hospital due to the need to protect herself from coronaviruses. The surgeon had told me that things weren't looking good and I was just there, paralyzed in place.

The surgery was a success two weeks later. She sounded like she still can't believe her luck.

I’m not saying that I would necessarily have made a different decision – but I would have liked to have been involved in that decision

Fry has been out of the hospital for a long time. I don't think it's too grandiose, but I think my view of the world has changed over the last couple of years. There is a nice line about life being an experience to be had.

She is happy that Fry is alive, but she is not sure how the risks were communicated to her.

She says that she was never given the numbers in order to choose.

Fry says that it was presented as a possible side-effect but that she would be lucky to have terminal cancer. She was asked if she wanted to live or die, and she chose the latter. She says that she didn't realize that there was an entire series of steps between the two.

Fry was able to pay for an experimental surgery that alleviated the impact of the condition. She didn't fully understand the feeling that she was steered towards an outcome.

I would have liked to have been involved in that decision, but I don't say that I would have made a different decision.

The importance of acting as your own advocate within the health system was highlighted by Fry.

There is a patriarchal approach to medicine outside of maternity where we just nod and agree and wonder if it's right for us. She breathed a sigh. It's too much to ask that you understand the risk of long term problems.

With Nina in the Horizon documentary Making Sense of Cancer.

With Nina in the Horizon documentary Making Sense of Cancer. Photograph: Curious Films/BBC

Fry suggests that patients who needed to make consequential decisions about their health would be able to sit down with a consultant who had a strong grasp on probabilities. How can we find the best path for you, and what aspects of your life are you most interested in preserving? For me, that's what informed consent is.

It takes more than resources to reach an understanding.

Fry says you are not going to get anywhere if you don't understand other people. You are both playing tennis on the same court.

She made a documentary about Britons who had refused the Covid-19 vaccine. Fry deserved a BAFTA for being the most patient TV host according to one reviewer.

She said that she learned that she was not as patient as she thought. I was probably more respectful of unvaccinated people than my peers.

The black woman from south London who spoke to Fry said that the vaccination centers looked like prisons.

She wanted to know why you would put yourself in that kind of environment. I didn't agree with her more until she said it.

As a response to her concern, doctors tried to show her figures about the vaccine's safety. Fry says that there is an emotional response and that he needs to understand that.

If you want people to go with you, you have to make them feel included and listen to them.

The most obvious example of this is the flu. Fry had set out to predict the impact on the show. Two years later, the large-scale data collection she led in the citizen-science experiment was applied to Covid-19 research.

During the government's press conferences, she shouted at her TV as impenetrable graphs were shown at rapid pace. She felt that statistics were being used to give themselves an air of authority. They used this as a way to close off the discussion because people find it intimidating. I don't think that was a good idea.

Hannah Fry

‘There is a much more patriarchal approach to medicine outside of maternity, where we just sort of nod and agree.’ Photograph: Alicia Canter/The Guardian

She pulled out her hair as her car approached the radio station. She says that trust now has to be more about a relationship than it used to be.

I think that is the only way to get people to believe you, because you have to be transparent about what you are not sure about.

Fry is able to focus on the positives with her new series. This is genuine but well-founded glee at the things that we have accomplished.

It might show us how much we don't take for granted. Fry doesn't need to think about 1.5C when I ask for a stat that keeps her up.

I believe there is another version of the future, one where we use artificial intelligence to take salt out of water, or turn the Sahara back into a rainforest.

I want to know if she could understand one aspect of math.

Fry says that if something has a 95 percent chance of happening, you shouldn't be surprised.

The new show is called Secret Wonders of the Modern World.