You Didn’t Get Softer. You Ran Out of Room.
Mind · The Reading Room, Vol. 29 · 7 min read · Why it is the parking machine and not the funeral, what the sleep research actually measured, and one thing to stop doing about it
Based on the published research of Andrea Goldstein-Piekarski, PhD — Assistant Professor, Department of Psychiatry and Behavioral Sciences, Stanford University, whose lab studies how sleep loss reshapes emotional reactivity. Faculty profile
Why do I cry at small things has an answer that fits the pattern exactly: it is the blocked errand rather than the sad news, and short sleep is what turns the volume up on precisely that category.
The car park machine at the hospital. Third attempt. Card declined, then declined, then the screen went back to the beginning and asked me to enter my registration again.
I cried. Standing up, holding a ticket, in front of a man in a fleece who was waiting to use it and who very kindly pretended to be reading a poster.
What I want to point out is what I had done ninety minutes earlier, which was sit in a consultant’s office and hear something serious about my father, and take notes, and ask two sensible questions, and thank her.
Composed for the consultant. Undone by the machine. And then, obviously, deeply embarrassed, which was the part that actually ruined the afternoon.
The short answer: why do I cry at small things is the wrong shape of question, because the events are not random and they are not the sad ones. Research on doctors working through sleep loss found something specific: shortened sleep amplified negative emotional responses to events that blocked a goal, and dulled the positive response to events that helped one.¹ Blocked, not sad. The parking machine is a blocked goal in its purest form. You have not become more emotional. The budget that used to absorb an obstruction has less in it.
The skim version
- Zohar and colleagues followed 78 medical residents with wrist monitors and called them three times a day to catch emotional reactions in the moment.¹
- After sleep loss, negative reactions to disruptive events were intensified, and fatigue with them.¹
- The same sleep loss reduced positive emotion after events that went well.¹
- Their model is a cognitive-energy one: handling an obstruction costs something, and short sleep lowers what is available to spend.¹
- The trigger category is obstruction, not sadness, which is why the machine gets you and the consultation does not.
Why do I cry at small things and stay composed for the big ones?
Because a big thing arrives with a role attached, and an obstruction arrives with nothing.
In the consultant’s office there was a job. Listen, write it down, ask the two questions, do not make this harder for anyone in the room. Jobs are structure, and structure is cheap to run. You have been doing versions of that job since you were twenty-six.
The machine has no job in it. There is nothing to be good at. There is only a thing that will not let you leave, at the end of a day when leaving was the only remaining item.
And this is where the finding earns its place, because it did not say sleep loss makes you sadder. It said sleep loss intensified negative emotional reactions specifically after events that got in the way of what somebody was trying to do.¹ That is a much narrower and much more recognisable claim.
What the sleep research actually measured
Most sleep and mood research asks people how they feel at random moments. Zohar’s group did something better. They wore actigraphs, which record sleep from movement, and they were called three times a day for three days running and asked about specific things that had just happened at work.¹
That design is why the result is usable. It ties a particular emotional reaction to a particular event, rather than to a general mood at four in the afternoon.
What came out was the pattern above: after short sleep, goal-blocking events produced stronger negative reactions and more fatigue, while goal-enhancing events produced less of a lift than they would have.¹ Both directions flattened toward the bad end.
The authors called it a cognitive-energy model.¹ Which is a technical way of saying the thing every woman reading this already suspects: getting over an obstruction is work, and you have been paying for it out of an account that has not been topped up in some time.
Between us
One study is carrying this piece and you should see it clearly. Seventy-eight medical residents, tracked with wrist monitors every six months across the first two years of residency, with emotional reactions sampled three times a day for three days at a stretch.¹ It is a good design and I trust the shape of what it found.
Being fair about it: those residents were 26 to 39 years old and 67 per cent of them were men. Not one of them was a fifty-three-year-old woman with a father in hospital and a temperature regulation system doing something new. The paper also reports a genuinely odd extra result, that sleep loss raised the overall baseline for positive emotion even while worsening the reactions, which nobody has fully explained. I am giving you the mechanism because it fits what the parking machine does. I am not giving you a study about women your age, because as far as I can find, it has not been run.
If the account has been running low for long enough that you cannot remember what full felt like, the useful question is what is draining it rather than why you cried. The Quiet Audit is a private ten-minute pass through exactly that. Start here.
Which events do it, and which ones do not
| Sets you off | Does not | |
|---|---|---|
| Typical example | The machine, the reschedule, the file that will not open | The diagnosis, the difficult phone call |
| What it is | Something blocking a goal you were mid-way through | Something serious that comes with a role to perform |
| What it costs | Energy you do not have, spent on nothing | Energy you do have, spent on something |
| How you explain it after | I am being ridiculous | Anyone would have found that hard |
The bottom row is the expensive one. The obstruction gets read as evidence about your character precisely because it was trivial, when the triviality is the whole point of the mechanism. Depletion that does not look like sleepiness is easy to miss, and carrying other people’s states all day is one of the quieter drains on the same account.
What to stop doing, which matters more than what to start
Stop explaining it in the moment.
The apology to the man in the fleece, the “sorry, I’m being silly,” the little laugh that is meant to give everyone their afternoon back. That performance costs more than the crying did, and it is the part you will still be thinking about at nine that evening.
What to do instead is smaller than you would like. When it happens, note one thing, silently: what was blocked. Not how you feel about crying. What you were trying to do when the thing stopped you.
The reason is that the answer is almost always a reading on a gauge. Leaving the hospital. Getting the shopping in before six. Ending the day. Naming the blocked goal turns the episode into information about your load, which you can act on, instead of information about your character, which you cannot.
Then let it be a Tuesday. The reflex to apologise for taking up space has its own history, and this is one of the places it shows up most reliably.
The source for this piece
Andrea Goldstein-Piekarski, PhD
Assistant Professor in the Department of Psychiatry and Behavioral Sciences at Stanford University. Her research uses brain imaging to trace how sleep loss reshapes the circuitry that regulates emotional reactions — the mechanism this piece is built on.
What we read: the underlying data is Zohar, D., Tzischinsky, O., Epstein, R., & Lavie, P., Sleep (2005);¹ Dr. Goldstein-Piekarski’s independent programme of research on sleep and emotion regulation is cited for the mechanism.
Where to follow her work: Stanford profile
Who else has measured this
One study named the pattern in medical residents. It is worth knowing whether the mechanism travels beyond that one group.
The original team included Prof. Peretz Lavie (Wikipedia · ResearchGate), a Technion sleep scientist whose decades of circadian research helped establish sleep loss as a measurable driver of daytime function, not only of tiredness. The team also included Dov Zohar, PhD (ResearchGate · Scholar) of the Technion’s Research Center for Work Safety & Human Engineering, and Orna Tzischinsky, PhD (author profile) of Emek Yezreel College.¹ Contemporary work by researchers including Dr. Goldstein-Piekarski has since used brain imaging to show sleep-deprived amygdala reactivity rising to exactly the kind of minor obstruction described here.
Two eras of the same finding: a 2005 field study of residents, and current imaging work showing the mechanism in the brain itself.
Composed for the consultant. Undone by the machine.
Questions worth having an answer to
Is this hormonal?
It can be part of it, and the transition genuinely affects mood and sleep. What is worth resisting is filing the whole thing under hormones and stopping, because the mechanism above operates independently and responds to different things. The anger version of this question is worth reading alongside it.
Why am I embarrassed rather than upset?
Because you were competent in the room that mattered and undone by a machine, and the mismatch reads as a verdict. It is not a verdict. It is the order in which an energy budget gets spent.
Does this mean I am depressed?
Crying at obstructions when you are underslept is not, by itself, a sign of depression. What would be worth taking seriously is a persistent low mood most of the day for weeks, losing interest in things you normally like, or a change in how you are eating or sleeping that has settled in rather than come and gone.
Will more sleep fix it?
It is the most direct lever the research points at. It is also, for most women in the middle of this, the least available one, which is why the note-what-was-blocked habit matters. It works on the nights you did not get.
The one move
The next time it happens, do not explain yourself to anybody standing nearby. Instead, name silently what was blocked. Four or five words. Then carry on with the errand.
If what is being blocked turns out to be the same thing every time, that is worth seeing written down. The Quiet Audit is a private pass through what your week is actually spending. Start here.
On the researcher. Andrea Goldstein-Piekarski is a psychologist and neuroscientist, not a general practitioner: her programme of work explains the mechanism reviewed here, and the 2005 Zohar study it is paired with is a field study of medical residents rather than of women in midlife.
Sourcing, disclosure and disclaimers
This is not medical advice. Blue Leaf Journal publishes general information for a general readership. Nothing here is a diagnosis, a treatment recommendation, or a substitute for care from a clinician who knows your history.
We are not clinicians. Blue Leaf Journal is an independent publication. We read published research and translate it. The findings belong to the researchers and institutions named and linked above; the plain-English rendering is ours, and so is any error in it.
No affiliation and no endorsement. Blue Leaf Journal is not affiliated with Andrea Goldstein-Piekarski, Dov Zohar, Orna Tzischinsky, Peretz Lavie, Stanford University or the Technion. None of them has reviewed, approved or endorsed this article, and none of them is responsible for it. They are cited because their published work is the evidence for what it says.
No commercial relationship. Nobody named above paid for or was paid for this coverage. There are no affiliate links, no sponsored placements and no gifted products in this article.
How this was checked. Every figure above is drawn from the primary papers, each linked in the references, and can be verified there. Sources were checked on 6 September 2026. If you find something we have got wrong, write to jobrennan@blueleafjournal.com and we will correct it and say that we did.
References
1. Zohar, D., Tzischinsky, O., Epstein, R., & Lavie, P. (2005). The effects of sleep loss on medical residents’ emotional reactions to work events: a cognitive-energy model. Sleep, 28(1), 47-54. Read the study
Jo Brennan writes the Mind and Load desks at Blue Leaf Journal: the overthinking, the noticing, and the jobs that are technically nobody’s and therefore hers. She has stopped apologising to strangers in car parks. She has not yet stopped apologising to the machines themselves, which she is choosing to regard as a separate project.
Written by Jo Brennan for Blue Leaf Journal. Updated: 29 August 2026.
