So, what's next? So simple a sentence, and yet perhaps the most terrifying question in the English language for students nearing the end of their doctorate. Should I do a postdoc? The guilt sets in. Didn't we all tell our graduate-school admissions committees that we were planning careers in academia? Aren't we newly minted PhDs now supposed to be aiming for that coveted assistant professorship? There, but for the long and treacherous postdoctoral road, I go.

And yet, against all my best intentions, I'm on that very road. If you'd told me two years ago, in the midst of my mid-PhD slump, that I'd be continuing in research through a postdoc, I would have laughed, and then cried, and then quit and returned to my native Australia. What went wrong?

I'll tell you — it's the allure of making a difference. I hoped to do so with my doctorate on cardiac arrhythmias, but I foresee only incremental improvements to existing therapies. Now I'm switching fields completely, researching nutrition and human body composition regulation, partly because addressing malnutrition and obesity promises to mitigate global public-health problems.

So, I'm giving myself two years, three at the most, to determine whether I can indeed make a palpable difference. Will my published articles effect change? Will mixing with experts excite me? Will my work have public-policy implications?