[BenG]

This was quoted in another thread.

We are what we pretend to be, so we must be careful about what we pretend to be.
-Kurt Vonnegut, Mother Night

and this could perhaps have a similar interpretation

O body swayed to music, O brightening glance,
How can we know the dancer from the dance?
-W. B. Yeats, Among School Children

and

Pretend to be good always, and even God will be fooled.
-Kurt Vonnegut, God Bless You, Mr. Rosewater