One of my supervisors during my PhD gave me a strong piece of advice at some point in my final year. It’s been a couple of years, so I’m paraphrasing here.
“It doesn’t really matter what you do in a postdoc,” he said, pausing briefly, to then continue “If you really want to stay in science, you have to just take the opportunity that presents itself. If you read and work on something long enough, you will learn to love it.”
My PhD advisers have been great, and I have gotten excellent and very complementary supervision from all three of them. But on this particular point… I could not agree LESS! I think I replied something along those lines to him right away, but otherwise my face would have given it away. My face doesn’t lie. And usually I’m to honest for my own good anyway.
In fact, I think it matters a lot what you choose, and perhaps even most at the point where you are choosing your first postdoc.
First of all, postdocs are tough, and you get very little reward for what you do. Doing something you do not fully support will make it a tough ride. (All science is tough, but for a PhD at least you get rewarded with a title you can put next to your door, for whatever that’s worth)
Second, sometimes you may have found during your PhD that your subject was not fully you. Perhaps you may have found yourself more interested in certain details, or perhaps even in the bigger picture. After finishing the PhD, it might be a good thing to look around for something that better matches your interests. Often this is a real possibility.
Third, during a PhD you generally do not develop your own research line yet. (Some may) This is, however, more likely to happen in your postdoc(s). You may run first experiments that are really your new thought babies. You may start writing a grant to explore things further. What good is choosing something you are not into so much then? I’m not saying its not possible. (I can have ideas about stuff I don’t like to do, too) I just think that developing a research line and spending the next five to ten years of your life on something that you don’t necessarily like – under the assumption that the love will grow – may be quite a risk to take.
Lastly, roughly one third of your week is spent on work. That is a lot of time. Better make it about something you love. I have in the past spent many work weeks in places that I did not want to be in just so I could pay the bills. In my experience, having a job that you dislike creates a lot of spillover effects into your private life. For instance, when I worked for a couple of months in a wet wipes factory – among others placing plastic lids on packs of baby wipes, simply because the technicians were too lazy to screw on the available device that would do this automatically – I became a very toxic person and developed a lot of somatic trouble because of it. I’d rather come home with a smile and be motivated to go back the next day, or put in the extra hour when that could get the job done.
I would not advise anyone to just take a job randomly. Call me a hippie, but I’m more of the ‘follow your heart’ and whatever. In the end it may be true that the ‘academic result’ will be the same, but I’m convinced you will find yourself a lot happier if you follow your instincts and do what you love.