You may or may not know about Family Guy. But in this youtube video of Family guy animated series, around 3:30, Stewie [son] was accidentally beaten by his father, Peter. Then he yell his father like following,
You can beat me but I am who I am.
What does "I am who I am" mean? Is it idiom?
"I am who I am" is similar to "I gotta be me" - it means that there are characteristics, habits, thought patterns (e.g., biases) or hopes/dreams that are so much a part of you that it is either "impossible" or very hard to change them (or, you don't want to change them because it feels natural/right to you, even if it will, on occasion, lead to negative outcomes).
I didn't see the episode in question, but it seems like Stewie was beaten (or feels he was beaten) for a specific action or statement he made and he is saying something like "I don't like this outcome/consequence of my action/statement, but I cannot or will not change how I act).
I (native speaker of Canadian English) would consider it an idiom. Similarly, if you are talking about someone else, you could say: "He is who he is" (not as common), "That's Stewie!", "That's Stewie for you", "You can't teach an old dog new tricks", or "A leopard never changes his spots"
Well, it seems that such sentence is originated in the Bible (Exodus 3:14)
I am that I am is a common English translation of the Hebrew phrase אֶהְיֶה אֲשֶׁר אֶהְיֶה, ’ehyeh ’ăšer ’ehyeh ([ʔehˈje ʔaˈʃer ʔehˈje]) – also "I am who I am", "I am what I am" or "I will be what I will be" or even "I create what(ever) I create"
According to "I Am Who I Am: An Autobiography of God" by Rev. Thomas O’Donnell
Depending on your inflexion, your body language, and how the listener or the reader interprets them, those simple words can have so many different meanings. "I AM WHO I AM" - an arrogant, stand-offish, remote, distant comment that can be interpreted as "None of your bussiness who I am. I said it. You do it". Or "I AM WHO I AM" can have a softer edge to it, something like: "I'm sorry I can't articulate who I am any more clearly for you - I truly wish I could - but mortal, finite human words can't capture the essence of the infinite so let's just leave it at I AM WHO I AM. Sorry"
That been said, I have seen the video, the complete sentence is
You can beat me but I am who I am
Usually Stewie is an arrogant and stand-offish character with egomaniac tendences. He may play to be God in other chapters of the series. But in this occasion, what he is saying is that his father can beat him but that is not going to change who he is.
I'm not sure about the double meanings but I think that he may be talking about being gay, homosexual. His father can beat him but homosexuality can't be "cured" and less of all with violence.
