
“The most exhausting thing in life, I have discovered, is being insincere.”
Source: Gift from the Sea (1955), Ch. 2; part of this statement has often been paraphrased: "The most exhausting thing in life is being insincere."
Context: I find I am shedding hypocrisy in human relationships. What a rest that will be! The most exhausting thing in life, I have discovered, is being insincere. That is why so much of social life is exhausting; one is wearing a mask. I have shed my mask.