Why do you work on the science you work on?

What was the decision-making process? How did you make the choice?

Early in my research career, I discovered that I loved working with statistical inference and building the software to do it. I had chosen my PhD because I knew I was interested in astrophysics and I was offered a place at a good department to work on observational cosmology (which I found and still find fascinating). Gradually over the years my horizons have broadened, to the point where I now work mainly on medical and biological data. But the key point is that I'm using statistical inference and programming to do science.

I certainly didn't see this path coming - it evolved.

I suspect this is true for a lot (maybe even most) scientists. Maybe the subject was something that interested them during their degree. Or perhaps it's what they're trained for, given the choice of undergraduate degree they made. That's sobering - the choice you made aged 17 can define your entire career. Anyone else want a 17-year-old picking your career for you? Thought not...

My guess is that many people aren't sure what to do next. They enjoyed their undergraduate degree and therefore (quite reasonably) decided to do a masters in the same or a similar subject. That also turned out to be interesting and, still lacking inspiration as to a career direction, a PhD beckoned (perhaps they were even offered a place by their Msc supervisor, making it an easy option). Suddenly, they're in their mid-twenties, have a doctorate and almost a decade of training in an academic subject. Sounds like a good basis for academia, so off they trot.

Some people want to stay at the same university and this affects their choice of subject (I'll admit to this a little bit). Given a choice of several interesting topics, they take the one that also allows them to stay where they want to be.

Perhaps the subject in question was/is an up-and-coming area with the prospect of lots of interesting science to work on and important problems to tackle. This seems like a not unreasonable consideration.

And of course some people have a burning passion for the subject (something which strikes me as a very good reason indeed!).

As you progress through your career, you'll learn more about what your chosen subject is really like. Are the scientific challenges important? Is it well-funded? What do you really enjoy doing on a day-to-day basis? And do you try to change things in response to this knowledge? What if after five years in one field, you realise that another field might suit you better for whatever reason. Would you change?

I once read a suggestion that in life you shouldn't pick a good destination, but rather focus on a good direction in which to go. The point is that as you live and experience life and learn from it, you'll be better able to make future decisions about where to go. If you pick your path through life now and stick to it, you'll have to turn down all those unexpected opportunities that occur tomorrow. And the You of 5 years time is probably a better judge of where you should be going at that point than you are right now; so why not defer to your (future) superior judgement?

And the point of all this? Think about why you work on the things you work on. And be willing to be flexible. Even if your current plan is a good one, you might happen upon an even better one tomorrow!