I hadn't thought about this for a long time... untill today

From Shakespeare's Othello, 1604:

IAGO:

It is as sure as you are Roderigo,

Were I the Moor, I would not be Iago:

In following him, I follow but myself;

Heaven is my judge, not I for love and duty,

But seeming so, for my peculiar end:

For when my outward action doth demonstrate

The native act and figure of my heart

In compliment extern, 'tis not long after

But I will wear my heart upon my sleeve

For daws to peck at: I am not what I am.