Niall Tubridy has been a neurologist for over 25 years, and still he discovers startling and bizarre insights into the human brain, something he says can feel "scary" at times.
While the fear that one complaint that he has just encountered may have been missed years earlier is a valid one, Niall - who is Ryan Tubridy's older brother - says that neurology is all about "humanity", and this is what keeps him fascinated in the ever-shifting world of the brain.
Speaking on Today with Seán O'Rourke earlier this week about his new book, Just One More Question: Stories From A Life In Neurology, Niall outlined some of the most bizarre ways to test the brain's health, his favourite neurological conditions and what role a hair straightener played in diagnosing a patient.
During his years working as a neurologist at St Vincent's Hospital in Dublin and one of the leading national experts on multiple sclerosis (MS), Niall says that "a very significant proportion" of patients who see him are not genuinely sick, but worried that they are.
"But that's international. It's not just Ireland."
This became clear following the popularity of the "ice-bucket challenge", the social media trend that sought to raise awareness for Amyotrophic Lateral Sclerosis (ALS). After this, the awareness progressed to "hyperawareness", prompting many people to worry they could have the disease.
"I think there was a very set group of people that I saw anyway that were young men, usually had kids recently and they look into their children's eyes, then hear about the ice-bucket challenge, then hear about motor neuron disease for the first time and go 'oh my god, will I be there for my children?'
"And you see the same with young women who have had children for the first time. They seem to worry about MS more than anything else. So it's a bizzare psychological thing."
For Niall, spotting someone with a neurological condition doesn't take much testing at the best of times, as he can tell from certain signs whether a person has a condition. For instance, he can usually spot someone with Parkinson's by the time they sit down.
"You watch people, how they walk, how they're dressed, how they respond to a doctor. Most people are still a little bit wary of it, not frightened of ... and so you see how quickly they get up, how quickly they take off their coats, if they're all calm and casual or if they're very nervous."
Of the more bewildering tests a neurologists can perform, Niall points to the Babinksi sign as one of the more fascinating. It involves scratching toes.
"I've got a bit of a hard time for some patients when they come in with a headache and I start scratching at their feet. Basically when we're born, when you scratch a baby's toe, the toe will go up for the first year of their life.
"After the first year or so, they've laid down a nervous system like cables and whatever else, and you scratch their toe ... and their toe goes down.
"But when the nervous system may fall apart a little bit later on in life, you scratch the toe and it goes back up to the baby state. It's one of the most important signs in neurology."
Niall's sense of wonder at the human brain is enormously clear even with almost three decades of work in the field under his belt, but giving a patient bad news is still an upsetting part of it.
"It's a significant part of the job, but there's a lot of good news, as well", he says.
For example, as an expert on MS - which predominantly affects women in their 20s and 30s - he has had the pleasure seeing women, whom he had given the diagnosis of MS, go on to have healthy babies, something that in previous years was advised against.
"In the 60s, I presume, but certainly in the 70s and early 80s neurologists didn't know what the future would hold, we didn't have the treatments we know have for people with MS. As a result - trying to protect ourselves as well as pretending to protect the women - we often said maybe you shouldn't have children, which was crazy in retrospect.
"We want everyone to live as normal a life as possible."
When it comes to advising people after getting a bad diagnosis, he tells patients "try to live with it in parallel with your normal life rather than carry it heavily on your shoulders for the rest of your life".
The treatment for MS has come a long way in recent years, with more advanced medications becoming more available.
"In MS when I started we would give people evening primrose oil. I don't know why in retrospect but apparently people said it worked. It didn't. Now we've got three shelves of treatment, like chocolate bars, going from light chocolate to dark chocolate to even darker chocolate.
"When I was training my senior colleague said 'Don't go into neurology. You can do nothing for anybody'."
A hair straightener disproves this claim, as Niall puts it. He recalls in the book that a patient came into his office saying that she could only straighten one side of her head as her arms would tire when doing the other side.
"She said 'my brother starts calling me Sideshow Bob' because one side of her hair was all curly and the other side was all straight'.
"In essence what was wrong with her, was she had a little extra rib and as a result when she put her hands above her head she trapped the nerves and the blood supply and her arm would tire."
A simple procedure righted this, but it proved to Niall that there is always a new way to learn about patients, and this is what makes neurology so endlessly fascinating.
To hear more about some of the most bizarre neurological conditions, as well as why people jumping in the Irish Sea can lose their memories, listen back to the interview above!