In these lines, Iago reveals that he is deceitful and self-serving. In response to Roderigo's saying that he would not serve Othello, Iago clarifies that he really doesn't serve Othello; he's always out for himself and himself alone.
Iago first mocks those "duteous and knee-crooking knave[s]" who genuinely try to do their best for their masters, serving them above themselves, only to be turned out in their old age without any reward. He says they deserve a whipping. In opposition to these, he ranks himself with those who "keep yet their hearts attending on themselves" and work for their own advantage even as they act out the part of serving their masters faithfully. He says that he follows Othello only for his own purposes, not out of loyalty. He swears that he will never show what he really believes in his outward actions.
"I am not what I am" means "I am not what I appear to be."
In Act I of Othello, Iago says to Roderigo:
I am not what I am. (I.i.57–65)
The line is verbal irony (
(The entire section contains 3 answers and 579 words.)