The first time when I remember I didn’t start paying attention to hydration because of a scientific paper or doctor recommendation. I started paying attention because I got tired of feeling tired. Not exhausted, not feeling horrible. Just slightly below where I knew I should be.
If you’ve worked in technology long enough, you’ve probably experienced something similar. You sleep seven or eight hours. Work is busy but manageable. Nothing major is going wrong. Yet by mid-afternoon your brain feels slower than it did in the morning.
You read the same paragraph twice. You postpone decisions that should take two minutes. The coffee helps for a while, but not for long.
For years, I assumed that was simply part of modern work. Meetings, deadlines, travel, constant context switching. That’s just how life feels when you’re busy, right?
Maybe. But not always.
One thing that surprised me over time was how often the explanation turned out to be embarrassingly simple.
I remember sitting through a full-day architecture workshop a few years ago. Nothing unusual. A room full of engineers, diagrams covering whiteboards, discussions jumping from cloud infrastructure to security to delivery pipelines. Around lunchtime I noticed I was struggling to stay mentally sharp.
The odd thing was that I wasn’t hungry. I wasn’t sleep deprived. I wasn’t particularly stressed. Then I looked down at the bottle beside my laptop. I had barely touched it.
That wasn’t some magical moment where everything suddenly clicked into place. But it started a pattern I noticed again and again. On days when hydration slipped, performance usually slipped too. Not dramatically. Just enough to matter.
Small deficits create bigger problems than we think
Most people imagine dehydration as an extreme event. A marathon runner collapsing in summer heat. A hiker stranded without water. Someone ending up in the emergency room.
That’s not what I’m talking about.
What I’m talking about is the version that shows up in ordinary life. The version where you feel slightly off but can’t quite explain why.
Thousands have lived without love, not one without water.
W. H. Auden1
You wake up feeling less refreshed than expected. A task that normally feels easy requires more effort. Your concentration drifts during meetings. Your workout feels strangely heavy.
Nothing is serious enough to raise concern. Yet the entire day feels a little harder than it should. What makes this tricky is that humans adapt incredibly fast.
Give someone a mild problem for long enough and they’ll start treating it as normal. I’ve seen this in myself. I’ve seen it in colleagues. I’ve seen it in family members. People often search for complicated explanations before examining the obvious ones.
The strange relationship between technology and water
One thing I’ve noticed during my career is that the technology industry has become exceptionally good at optimizing everything except the humans doing the work.
We measure deployment frequency. We measure system latency. We measure cloud costs. We measure productivity metrics. We track sleep. We track steps.
Some people track dozens of health variables every single day. Yet I’ve lost count of how many times I’ve walked into a meeting room and seen six engineers with coffee cups and no water. There’s an irony there.
We spend our careers designing reliable systems while often neglecting the maintenance requirements of our own bodies. The truth is less exciting than most people would like.
Human performance is biological before it is digital. Before productivity apps. Before AI assistants. Before optimization frameworks. Your brain is still running on sleep, nutrition, movement, and hydration. Ignore those long enough and eventually everything else becomes harder.
| Factor | Effect on Hydration Needs |
|---|---|
| Exercise | Increases fluid loss through sweat |
| Hot weather | Raises water requirements |
| Body size | Larger individuals typically need more fluids |
| High-protein diets | Often increase fluid requirements |
| Age | Thirst sensation may decrease |
| Illness | Fever and infection increase fluid loss |
The research supports what many people already feel
The science behind hydration has become increasingly difficult to ignore.
A 2025 study published in the European Journal of Nutrition found significant associations between hydration status and cognitive performance, including memory and overall cognitive function.
Another study following nearly 2,000 adults in Spain found that poorer hydration status was associated with greater cognitive decline over time. More than half of participants showed signs of physiological dehydration.2
More than half of participants were physiologically dehydrated. More than half. That suggests we’re not discussing a niche problem. We’re discussing something that may affect a huge portion of the population without them realizing it.
Lessons from tennis courts and airports
Some of my clearest hydration lessons came outside the office.
Tennis has a way of exposing mistakes quickly. On a cool day, you can get away with poor hydration for a while. On a hot day, the bill arrives much sooner. I’ve had matches where my legs felt heavier than expected despite good sleep and decent preparation. Looking back, hydration was often part of the story.
Travel creates a similar effect. Anyone who flies frequently knows the feeling. You land after a few hours in the air and feel strangely drained despite doing almost nothing physical. The cabin environment doesn’t help. Neither does airport coffee becoming a substitute for water.
For years I treated that fatigue as unavoidable. Now I pay much more attention to hydration before and during flights, and the difference is noticeable. Not life-changing. Just noticeable enough that I keep doing it. That’s usually how worthwhile habits work.
The older I get, the more I respect fundamentals
I’ve become less interested in health trends over time. Not because innovation is bad. Because fundamentals keep winning.
Sleep still matters. Movement still matters. Nutrition still matters. Hydration still matters.
None of these topics generate much excitement. Nobody becomes famous for recommending a glass of water. Yet when I look at people who remain energetic, capable, and mentally sharp into later decades of life, they almost always take the basics seriously.
The longer I work in technology, the more I appreciate that reality. Complex systems often fail because simple things were ignored. Human beings aren’t much different.
Sometimes the highest-return improvement isn’t hidden behind a subscription, a supplement, or a new device. Sometimes it’s sitting in a bottle on your desk waiting for you to drink it.
