Imagine never feeling the pain of stubbing your toe, or the anxiety of a job interview.
That's life for Jo Cameron, who has been highlighted by doctors for having a mutation in a previously unidentified gene.
The 71-year-old, who lives in the Highlands, feels virtually no pain, fear or anxiety - and may even heal quicker than normal.
She only found out six years ago after being diagnosed with severe joint degeneration in her hip, despite experiencing no pain.
A year later, she then underwent surgery on her hand at Raigmore Hospital in Inverness and reported no pain afterwards, although the treatment is normally very painful.
Jo told STV News: "Although people were saying 'do you need painkillers?' and I said 'no', the look from the nurses was 'you should need painkillers'.
"The anaesthetist said 'this is an extremely painful operation, you're bound to need painkillers' - and I didn't.
"My father was the same, he was a jolly man who never seemed to get stressed about anything.
"He just bounced back. I just thought I was like him - I'd got a kind of role model in my mind so I never felt different."
Dr Devjit Srivastava, an NHS consultant in anaesthesia and pain medicine, diagnosed her pain insensitivity and she was referred to pain geneticists at UCL and Oxford University.
Scientists there conducted genetic analyses and found two notable mutations.
The researchers dubbed it FAAH-OUT and also found that the woman had a mutation in the neighbouring gene that controls the FAAH enzyme.
The FAAH gene is well-known to pain researchers, as it is involved in endocannabinoid signalling which is central to pain sensation, mood and memory.
Scientists have found that mice that do not have the FAAH gene have reduced pain sensation, accelerated wound healing, enhanced fear-extinction memory and reduced anxiety.
Jo experiences similar traits and said that throughout her life she often didn't notice cuts or burn until she could smell burning flesh and the injuries tended to heal very quickly.
She was given the lowest score on a common anxiety scale, and told researchers that she never panics, even in dangerous situations such as a recent traffic incident.
The pensioner also reported memory lapses throughout life such as forgetting words or keys, which has previously been associated with enhanced endocannabinoid signalling.
Jo said: "I had no idea until a few years ago that there was anything that unusual about how little pain I feel.
"I just thought it was normal. Learning about it now fascinates me as much as it does anyone else.
"I would be elated if any research into my own genetics could help other people who are suffering."
The researchers say that it's possible there are more people with the same mutation and urged anyone who does not experience pain to come forward.
Dr James Cox of UCL Medicine, one of the lead authors of the paper, published in the British Journal of Anaesthesia, said: "We found this woman has a particular genotype that reduces activity of a gene already considered to be a possible target for pain and anxiety treatments.
"Now that we are uncovering how this newly-identified gene works, we hope to make further progress on new treatment targets."