Each of us needs periods in which our minds can focus inwardly. Solitude is an essential experience for the mind to organize its own processes and create an internal state of resonance. In such a state, the self is able to alter its constraints by directly reducing the input from interactions with others. (p. 235)
Daniel J. Siegel, The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are
neuropsychology, solitude