You Can't Pour from an Empty Cup.

I learned many things about doing research the hard way. If there is one thing that was the worst among all, it is how late I came to understand the importance of taking care of my own well-being. I sincerely hope every PhD student can absorb this before they start the journey, because the costs of learning it from negative consequences are severe and often irreversible.

To begin with, I want to talk about the most attractive advantage of doing research: flexibility. If you ask ten faculty members “what is the most attractive advantage of research as a career?”, I bet that at least eight of them will tell you it is the flexibility. And you will notice what this means in practice from the first day of your PhD.

For many of the labs, you are typically not asked to be present at your office from nine to five, with no one checking badge swipes, and you have the full autonomy to choose when to work, what to work on, and when to take a rest. Our group, for instance, does not ask students to be present in the office. In fact, we even encourage students to work from wherever they prefer, and believe me, they (including me) really do take a flight to Honolulu and host the project meeting while enjoying the ocean view and sunshine.

Great, you might think. An ideal life. So what could go wrong?

“Am I Thinking the Right Way?”

I hope you still remember some of what we covered in the earlier chapters, that the PhD journey is stressful and challenging, mostly because of the substantial effort needed to transition to the mental models and master the critical skills that research demands.

Imagine that you are stuck drafting a logically coherent motivation after three months of reading hundreds of papers and conducting hundreds of revisions, and your advisor and collaborators can always identify logical gaps easily during the weekly meeting, while you could not have done so by yourself even after staring at the draft for hours. The confusion, stress, and anxiety accumulate day after day, week after week.

Understandably, you want to make changes. “Am I not spending enough time on research? Am I not trying hard enough?” With these common questions emerging in your mind, you start spending more time on research every day, thinking about research while having lunch, working out, hanging out, and sitting in front of the screen late at night, hoping the additional time can be translated into concrete research progress. The flexibility you possess grants all of these changes, but the consequence often goes the other way around.

For most junior researchers, they get stuck because they have not found the appropriate methodology to explore an unfamiliar research field, and the problem is rarely insufficient effort. Spending more time is probably the easiest attempt at a better outcome, but this is, I promise, one of the least effective and sustainable ways. Sometimes, junior researchers are just not aware of a smarter methodology, and the lessons in this series exist precisely for that purpose. “Am I thinking the right way?” is the question they should be asking.

The Guilt of Not Working

The wrong self-inspection questions lead to a subtler problem that almost no one warns you about. When your schedule is entirely yours and the boundary between work time and personal time has dissolved, every moment you are not working starts to feel like a moment you should be working.

Just think about it. While you are watching a TV drama, a thought creeps in: “I haven’t fixed the issues with the analysis, why am I not working?” While you are hanging out with your friends for dinner, you are actually half-present because your advisor sent the comments on your draft to you before you left home, and you are thinking about how to fix them all tonight. I am fully aware that many students choose to work during weekends even just for one or two hours, because the guilt of not working accumulates if they take a full day off, and it pushes them to sit back down at the computer to make the accumulation stop.

Junior researchers (and even some senior ones) are not aware that such guilt is self-reinforcing. The more you give in to it, the more the guilt trains you to believe that resting is stolen time – something you will feel guilty about. Not surprisingly, over weeks and months, the capacity to genuinely rest erodes, and you end up in a state where you are always partially working and never fully resting, which is worse for both your research and your health than a clean separation would be.

Learning to rest without guilt is a skill that takes practice, and it starts with recognizing that the guilt is a signal of a dissolved boundary, not a signal that you are being lazy.

The Three Invisible Drifts

The combination of the wrong question and the guilt of not working produces changes in your daily routine that are far more destructive than you would be aware of. I call them “invisible drifts” because they share the same mechanism: the changes are gradual, the consequences are delayed, and the damage has been quietly accumulating for months by the time it becomes visible.

Sleep. Many students choose to work during the evening because evening times are more personal, quieter, and less likely to be interrupted by others compared to daytime. The problem is, if you are still struggling with research tasks right before bed, your nerves are highly active, and your mind is filled with stress.

You could go to bed around 11:00 pm for a week, then around 11:15 pm the next week, because you cannot fall asleep easily and fifteen minutes does not feel like a big deal. A month later, you are going to bed around 11:30 pm and sometimes working past midnight. After three months, you are used to staying up until 2:00 am.

What makes the shift especially dangerous is that you often will not feel discomfort even after months of late nights, and you may even persuade yourself that you are more focused and hardworking than before. The consequences accumulate silently over a very long period of time, because they do not arrive right after the act, and because you are the one and only person managing your schedule, there usually does not exist a second person to warn you that you have pushed too hard.

For most people, the realization arrives only when the body shows obvious signals, for example, heart palpitations, stabbing pain in the heart, shortness of breath, muscle soreness, chronic fatigue. For some who choose to neglect those signals, the realization arrives with more severe illness, such as immune system disorders. By that point, your normal work is going to be impacted, and the recovery will cost you far more time than the rest you refused to take.

Sitting. Researchers have a specific occupational hazard that almost no one cares about until it is too late: lower back injuries. Almost every junior faculty I know suffers from lower back pain, and the differences are just in severity. Why is that?

Junior researchers commonly lose track of how long they have been sitting while focused on searching for information and solutions, and the same devotion that makes them good researchers keeps them in the chair for hours without interruption. If you are genuinely focused on a specific research task, like reading literature or drafting papers, you will not feel how fast time flies – but your lower back feels it, and you will, eventually.

As a person who has experienced severe lower back injuries to an extent that I could barely stand, and who spent more than a year in recovery (not completely recovered as of this writing), I would strongly suggest everyone be aware of the amount of time you sit continuously. Set a timer for 40 to 60 minutes when you start to work, then stand up and walk around for at least five minutes. Get a standing desk if possible, so that you can alternate between sitting and standing while continuing your work.

Eating. The same gradual shift that affects sleep and sitting affects nutrition. Meals get skipped because you are in the middle of something and do not want to break your focus. Typically, lunch happens at the desk while you are on a Zoom meeting, and dinner shifts later as bedtime shifts later. Over weeks, the decline is so gradual that you do not notice until your energy, your focus, or your health has measurably changed. Try to treat meals as fixed points in your schedule that research works around, and not as flexible interruptions that research can push aside.

What the Empty Cup Looks Like

The cruel irony of every drift described above is that you sacrifice your health for the research, and the sacrifice will degrade the very research you are trying to optimize. When you are sleep-deprived, your ability to think critically, identify logical gaps, and produce creative solutions drops measurably, and the decline happens before you feel tired enough to notice. When you are in chronic lower back pain, your body will constantly be pulling attention away from the work and toward the discomfort, and you need to spend much more time stretching and resting so as not to make things worse. When you are eating poorly or irregularly, your energy and concentration fluctuate in ways you cannot predict, and the hours you spend at the desk produce less and less.

The result is that you work more hours but produce lower-quality output, which creates more stress about the lack of progress, which pushes you to work even more hours, which deepens the drift further. It will be challenging for you to see clearly through the negative cycle because the decline in your judgment is part of the overall decline. I learned this lesson the hardest way, and genuinely do not expect others to repeat the mistakes that I have made.

More importantly, the consequences extend beyond the work itself. When you are running on empty, you become irritable with collaborators over small things, withdraw from friends and family who would otherwise give you perspective, and lose the social connections that help you notice how far you have drifted. The people around you can see the change before you can, but if you have already pulled away from them, their observations never reach you. An empty cup does not just fail to pour; it pushes away the people who would help refill it.