There is a pattern running through the biographies of creative people that is almost embarrassingly consistent: the most productive phases of their lives tend to involve withdrawal from normal social life.
Descartes developed his method of systematic doubt by spending a winter in a "heated room" (his phrase) in Germany, alone with his thoughts, discarding everything he had been taught and starting over. Emily Dickinson spent the last decades of her life almost entirely within her family home in Amherst, Massachusetts, refusing most visitors, and produced over 1,800 poems. Proust worked in a cork-lined room, mostly at night, cut off from the social world he was writing about. Newton developed calculus, the laws of motion, and the theory of gravity during a period of forced isolation at Woolsthorpe Manor while Cambridge was closed due to plague. Darwin spent his most productive years at Down House in rural Kent, deliberately away from London's distractions, following a strict daily routine of walks and thinking time.
This is not coincidence, and the psychologist Anthony Storr spent his career explaining why. In Solitude: A Return to the Self (1988), Storr argues that our culture's equation of psychological health with interpersonal intimacy is too narrow. The capacity to be alone is a genuine developmental achievement, and it is a precondition for the kinds of inner work that produce original thought. Sustained creative work requires what Storr calls "the cultivation of the inner world": developing a rich enough interior life that you can generate new connections and meanings from within, rather than requiring constant external stimulation.
The philosopher José Ortega y Gasset put it well: "We do not know what is happening to us, and that is precisely the thing that is happening to us." Creative withdrawal is, in part, the practice of stepping back far enough from the flow of events that you can actually see what is happening rather than just being swept along by it.
But there is a paradox at the heart of creative solitude that the Romantics noticed and mostly ignored. Genuine creative withdrawal is not simply isolation from other people. The writers and thinkers who did their best work in solitude were not cutting themselves off from human experience. They were cutting themselves off from the social performance of human experience in order to attend to its substance. Proust withdrew from Parisian society specifically to write about Parisian society. Dickinson's solitude produced poems that go deeper into human feeling than almost any other poet's. The withdrawal is in service of more genuine engagement, not less.
The Stoics called this the inner citadel: the capacity to retreat to a place of mental autonomy that does not depend on external circumstances. Marcus Aurelius governed an empire, fought wars, and dealt with plague, but he maintained his inner citadel through his journal, his regular practice of philosophical reflection. Solitude, on this view, is not primarily about physical location. It is a quality of attention that can, with practice, be maintained even in the midst of external noise.