Killingsworth and Gilbert’s 2010 Harvard study used an iPhone app to gather 250,000 data points from 2,250 participants at random moments throughout their days. People’s minds were somewhere other than their current task 46.9% of waking hours. The study’s headline finding — that mind-wandering predicts unhappiness — has been widely cited as evidence that it should be reduced. The research on what the mind is actually doing during that 46.9% tells a different story…

The prospective brain

Schacter, Addis and Buckner’s 2007 paper in Nature Reviews Neuroscience proposed that a primary evolved function of the default mode network is not to preserve the past but to simulate and predict the future. The hippocampal-DMN network retrieves autobiographical memories and uses them as building blocks for constructing plausible future scenarios — a process they termed constructive episodic simulation. Patients with hippocampal damage who cannot form or retrieve episodic memories are correspondingly impaired in their ability to imagine future scenarios in vivid, coherent detail. Memory exists, in this account, primarily as a simulation engine for the future.

Baird, Smallwood and Schooler confirmed the direct application: mind-wandering content is predominantly future-focused rather than past-focused, and this prospective mind-wandering frequently involves autobiographical planning — the simulation of personally relevant, goal-directed future scenarios. The frequency of future-focused off-task thought decreases as task demands increase. The busier the directed attention system, the less autobiographical planning the default system can perform.

What the wandering mind is actually doing

The DMN consists of two functionally distinct subsystems. A dorsal medial prefrontal cortex subsystem is engaged in introspection about mental states, social reasoning, and theory of mind. A medial temporal lobe subsystem handles autobiographical memory retrieval and future simulation. Together they support the brain’s system for maintaining, updating, and projecting the self-concept.

The medial prefrontal cortex — a core DMN hub — is specifically activated when individuals reflect on personal goals and values, plan future personal activities, engage in self-evaluative reasoning, and construct the narrative self-concept through which they make meaning of their choices. These are not random processes. When an entrepreneur’s mind wanders, the default system is running the self-referential cognitive processes through which strategic identity is constructed and maintained. What kind of business do I want to be building in five years? What am I becoming as an entrepreneur? These are not questions that directed analytical processing answers well — they are answered by the DMN’s self-referential mode, which is precisely what mind-wandering activates.

The delay discounting mechanism

Peters and Büchel’s fMRI study demonstrated that episodic future thinking — vividly imagined simulation of personally relevant future scenarios — reduces delay discounting through modulation of neural decision-making networks. Spontaneous episodic imagery predicted the degree to which participants shifted their preferences toward more future-minded choices. The mechanism operated through functional coupling between the anterior cingulate cortex and the hippocampus and amygdala — the future simulation produced an affective signal that made delayed outcomes feel real and emotionally present, counteracting the natural devaluation of future rewards.

One of the most persistent challenges in entrepreneurial decision-making is precisely this temporal bias — the pull toward immediate tactical action over long-term strategic positioning. Episodic future thinking is the cognitive mechanism that counteracts it. By vividly simulating the future in which a long-term strategic choice plays out, the entrepreneur makes that future feel present and affectively weighted in a way that analytical long-term planning alone does not produce. Mind-wandering is the spontaneous, unsolicited version of this process — the brain running its future-simulation capacity without being asked to.

The planning content of wandering

Kvavilashvili and Rummel’s synthesis of the spontaneous future thought literature found robust support for the pragmatic theory of prospection: when people engage in prospective thought naturally, they predominantly think about upcoming tasks and planned activities rather than simulating novel hypothetical scenarios. The content of spontaneous future thought is overwhelmingly near-future, goal-directed, and concerned with concrete personal activities. It is not strategic in the sense of long-range scenario planning; it is strategic in the sense of task orchestration — the continuous mental rehearsal and prioritisation of imminent personal and professional commitments.

When an entrepreneur’s mind drifts during a low-demand activity, the default system is not producing idle noise. It is rehearsing upcoming meetings, re-prioritising competing demands, and constructing the micro-strategic landscape of the next days and weeks. Filling every gap with phone-based stimulation — podcasts, social media, messages — systematically prevents this spontaneous cognitive task-management from occurring.

What busyness suppresses

Directed attention and default mode processing are functionally anti-correlated: the DMN deactivates when external demands increase. An entrepreneur fully task-occupied from morning to evening is neurologically suppressing the self-referential processing through which strategic identity is maintained, future scenarios are simulated, and goal priorities are updated.

The specific strategic processes suppressed by chronic cognitive occupation are not the same ones suppressed by creative incubation needs. They include the integration of autobiographical narrative, the maintenance of long-term goal salience in the face of immediate tactical demands, and the social cognitive simulation of how strategic decisions will land for customers, team members, and investors. These are strategic self-management functions, and they are exclusively the province of the DMN’s self-generated thought mode. They do not happen in meetings, on calls, or while scrolling. They happen in the 46.9% of waking hours that the Killingsworth and Gilbert study documented — which busyness eliminates.

Book worth reading on this

Stumbling on Happiness by Daniel Gilbert is the most accessible treatment of the human capacity for prospection — the mental time travel into personal futures that the DMN’s self-referential processing produces. Gilbert’s central argument is that the human ability to simulate future experience is both the most distinctive feature of the human mind and the source of the most systematic cognitive errors. For any entrepreneur trying to understand why they make the future choices they do — why long-term thinking feels so much harder than short-term thinking, and why the futures they plan for rarely feel the way they expected — this book provides the psychological framework with unusual clarity and wit.

If the dynamics described here are significantly affecting your wellbeing, speaking with a psychologist is the right next step. UK: Samaritans (116 123, free, 24/7). Mind (0300 123 3393). BACP: bacp.co.uk/search/Therapists. Crisis Text Line — text HOME to 741741 (US, UK, Canada, Ireland). International: internationaltherapistdirectory.com.

This article is for educational and informational purposes only. Sources: Schacter, D.L., Addis, D.R. & Buckner, R.L. (2007), Remembering the Past to Imagine the Future: The Prospective Brain, Nature Reviews Neuroscience, 8(9), 657–661. Baird, B., Smallwood, J. & Schooler, J.W. (2011), Back to the Future: Autobiographical Planning and the Functionality of Mind-Wandering, Consciousness and Cognition, 20(4), 1604–1611. Andrews-Hanna, J.R., Smallwood, J. & Spreng, R.N. (2014), The Default Network and Self-Generated Thought, Annals of the New York Academy of Sciences, 1316, 29–52. Peters, J. & Büchel, C. (2010), Episodic Future Thinking Reduces Reward Delay Discounting through an Enhancement of Prefrontal-Mediotemporal Interactions, Neuron, 66(1), 138–148. Kvavilashvili, L. & Rummel, J. (2020), On the Nature of Everyday Prospection, Review of General Psychology, 24(3), 210–237. Killingsworth, M.A. & Gilbert, D.T. (2010), A Wandering Mind Is an Unhappy Mind, Science, 330(6006), 932. Smallwood, J. & Schooler, J.W. (2015), The Science of Mind Wandering, Annual Review of Psychology, 66, 487–518. Kaplan, S. (1995), The Restorative Benefits of Nature, Journal of Environmental Psychology, 15(3), 169–182. Gilbert, D. (2006), Stumbling on Happiness, Alfred A. Knopf.