Life is for each man a solitary cell whose walls are mirrors.

"Tragic is the plight of the tragedian whose only audience is himself! Life is for each man a solitary cell whose walls are mirrors. Terrified is Caligula by the faces he makes! But I tell you to laugh in the mirror, that seeing your life gay, you may begin to live as a guest, and not as a condemned one!"—Act II, Scene I.

Eugene O'Neill  Lazarus Laughed, 1927