It was my dad who triggered my interest in science. It wasn’t really anything he said, or anything he did, but rather who he was. From quite a young age (I don’t remember when exactly), I knew that he was sick. He suffered from hemophilia—a genetic disorder that prevents your blood from clotting properly. In the most common variant of the condition (hemophilia A), the body does not produce enough of something called Factor VIII—a glycoprotein essential for blood clotting to occur. In some individuals it’s not the quantity of Factor VIII that’s the problem, but the quality: a faulty version of the protein is produced and it doesn’t do what it should.

If he cut himself, he would bleed for a very long time—this would be hours rather than minutes.

What did this mean on a day-to-day basis for my dad? Well, if he cut himself, he would bleed for a very long time—this would be hours rather than minutes. Being fully aware of his condition, he was obviously very careful not to cut himself. The one thing you have no control over as a hemophiliac, however, is spontaneous internal bleeding. He would often have a lot of joint pain—because he would be bleeding internally into his joints—and not be able to bend his arms or legs very well. The pain was severe and some days he could barely walk. Even on the best days, he walked like an old man.

There was no play-fighting, no bike rides, and we couldn't even go to the park and have a kick around with a football. I don't remember doing that even once (even though we were both football crazy—the only reason I'm a Manchester United supporter is because that's who my dad followed). We did play games, but we're talking snooker, pool, and darts—and that's why these days I'm occasionally accused of having a misspent youth when I do fairly well at these things! Even so, there were many days when even those activities were out of the question because my dad couldn't bend his arms.

Because of his condition, my dad hadn’t gone to school; he’d had some home schooling, but not a great deal (we’re talking 1940s/1950s coal-mining English town here). A lack of formal training combined with the physical manifestation of his hemophilia meant that he never had a regular job. Nevertheless he was naturally quite intelligent—he taught himself from scratch how to repair clocks and watches. He would fix them for relatives, friends, and friends of friends, and it would be done for the price of the parts plus a few pounds more—if you went to a jewelry shop it would cost at least ten times as much. Unless it was a Timex—apparently they were a nightmare to fix and he told people it would be easier for them to get a new watch.

I was fascinated with the bits and pieces that came out of a watch. How could all of those little parts even fit inside the case, let alone work together in harmony to plot out the passage of time in regular beats? I wanted to know how things worked—as many small boys do—and this was my own (very personal) introduction to taking things apart and putting them back together. My dad would sit on the sofa with his small wooden workbench in front of him—in fact it was more of a converted writing desk than anything else—and I would perch alongside him. He would carefully dismantle a watch to investigate what might be at fault and I would be allowed to play with one of his magnifying lenses and some spare parts salvaged from previous items that were beyond repair. As I got older, it was less about me being reminded to sit still and more about what each little bit in the watch did. I wish I remembered more—but these days if my watch needs a new battery, it goes off to the jeweler’s. And the next time my watch stops working, I'll just get a new one.

It was my introduction to rudimentary genetics: X and Y chromosomes and recessive traits.

But something else that really interested me was my dad’s condition. It was my introduction to rudimentary genetics: X and Y chromosomes and recessive traits. The history of hemophilia itself also fascinated me. We lived a simple life in a council house, but hemophilia was “the royal disease.” Royal! Through her children, Queen Victoria introduced the disorder to many of the royal houses of Europe. Perhaps the most famous were the Romanovs who, after turning to Rasputin to heal their hemophiliac son, met their bloody fate in a basement at the hands of the Bolsheviks.

My dad's treatment options were a little more traditional—and certainly had far fewer geopolitical consequences for Europe. One way of relieving the joint pain when it got too severe, or to stop a bleed that just kept going, was to make the trip to hospital, where he would be given an infusion of Factor VIII. This also intrigued me. My dad had this disease, but some clever people had figured out what the problem was and how it could be managed (there is no cure for hemophilia). This was a revelation to me. “Magic” is the wrong word, but it was certainly amazing. If it wasn’t for the fact that I am embarrassingly squeamish, I might have gone into medicine. (Seriously, much to my wife’s amusement, I can’t even watch the surgery bits on ER/Grey’s Anatomy/Casualty.) If it wasn’t going to be medicine, science seemed like a good alternative—but even so, it wasn’t a carefully thought out plan for what I wanted to be when I grew up. It just seemed like something I might enjoy doing.

So, Factor VIII was the answer, and it certainly improved my dad’s quality of life. For a while. It turns out that the early 1980s weren’t a great time to be a hemophiliac in need of Factor VIII treatment. For those of you who don’t know how the story ends, the name Ryan White might ring a bell. If it doesn’t, well, here goes. At that time, many of the blood products used to treat hemophiliacs were contaminated with HIV and many patients were infected—my dad included. It was a death sentence. I was fifteen when my dad died of AIDS. He was forty-eight.

Maybe the fifteen-year-old me thought that there might be some comfort in better understanding what had happened to my dad.

This didn’t trigger some kind of heroic lifelong quest, either to seek a cure or to avenge the sense of cosmic injustice that I felt. And it didn’t, in any conscious fashion that I can identify (even now), cement any pact I had with myself to be a scientist. But it did leave me wanting to know more about these short and scary acronyms that had turned my world upside down. Maybe the fifteen-year-old me thought that there might be some comfort in better understanding what had happened to my dad. More than twenty years later, I can tell you that there isn’t any.

Sure, I can (if I must) explain what happened to my dad in scientific terms, but knowing the how doesn't help with the why, or with the hole that it left in my life. As a teenager the world is actually quite simple (even if it doesn't seem that way at the time) and getting a better grip on what happened must have seemed like a step in the right direction. But now that I've lived a little more, I know what really hurts. My dad was at neither of my graduation ceremonies, he didn't see me marry the girl of my dreams, and he wasn't around for the birth of his granddaughter. And those are just the big obvious life events. It upsets me that I was never really a grown-up in my dad's eyes; and even though it sounds trivial, I never got to take him down to the pub, buy him a drink, and talk about grown-up things.

But life has to go on, and it does. I continued on the path of science. I worked hard, did well at school, and then went off to university to do a degree in chemistry and bioorganic chemistry (after a brief and spectacularly unsuccessful flirtation with a physics degree—I dropped out after just one week). I’ve been fortunate to work with some amazing people in some great places, and I’ve traveled the globe—but all of that is a different story for a different day. And even though I’m now an editor, I still consider myself to be a scientist. It’s not a job; it’s a state of mind.

When it comes to me and science, there wasn’t a eureka moment. It was a gradual embrace that had its roots in my childhood and, in particular, my dad’s illness. I may well have found my way to science even if things had been different—and how I wish they had been different. But things are what they are, and that being the case, there’s only one thing left to say. Thank you, Dad.

Stuart Cantrill is the chief editor of Nature Chemistry (http://www.nature.com/nchem) — but that's just the day job that helps feed his shiny-Apple-product habit. He lives with his wife and daughter in Cambridge, U.K., and on the rare occasions he gets a quiet moment (and hasn't fallen asleep), he blogs at stuartcantrill.com.

Illustration by Joe Wierenga.