An old favourite

"It is a lonely idea, a lonely condition, so terrifying to think of that we usually don't. And so we talk to each other, call each other, call each other short and long distance across land and sea, clasp hands with each other at meeting and at parting, fight each other and even destroy each other because of this always somewhat thwarted effort to break through walls to each other. As a character in a play once said, 'We're all of us sentenced to solitary confinement inside our own skins'. Personal lyricism is the outcry of prisoner to prisoner from the cell in solitary where each is confined for the duration of his life."

Tennessee Williams prefaced his play, Cat on a Hot Tin Roof with an essay entitled Person - to - Person. The above quote is taken from it. I first read it about three years ago and it still resonates.