" As Kethledge and Erwin explain, however, solitude is about what’s happening in your brain, not the environment around you. Accordingly, they define it to be a subjective state in which your mind is free from input from other minds. You can enjoy solitude in a crowded coffee shop, on a subway car, or, as President Lincoln discovered at his cottage, while sharing your lawn with two companies of Union soldiers, so long as your mind is left to grapple only with its own thoughts. "

― Cal Newport , Digital Minimalism: Choosing a Focused Life in a Noisy World