There are too many unknowns, too many factors that we may not have yet considered. Donald Rumsfeld coined this phrase in response to questions about whether terrorism intelligence collected by government agencies was being shared with all other security agencies.
Q: But seriously, Mr. Secretary, are you confident that all the intelligence gathered has been adequately shared, all the intelligence that Defense and the military has gathered has been adequately shared with other security agencies in the government?

Rumsfeld: Well, of course you don't know what you don't know. All I know is that we get a great deal of intelligence. We see that the individuals responsible for force protection in the United States and elsewhere around the world have it as rapidly as is possible. They then make their judgments as to how they're going to behave with respect to it.
(...)
I feel that we know what we know and we don't know what we don't know.
by SnakeMan25 March 1, 2010
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I don't know
You: wats 1+1
Your dumb ass friend: I don't know
by I don't know 666 February 23, 2018
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A subtle way of expressing how poorly you think of someone. A form of shade.

Coined by Mariah Carey, in 2003, when she was asked about whats he thought of Jennifer Lopez.
Samantha: "Weren't you best friends with Alana?"
Emily: "I don't know her"

Mary: "Are you and James still dating?"
Emily: "I don't know her"
by just like honey September 1, 2017
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A shady way of saying someone didn't exist in your world in your life and you don't like them . They are basic irrelevant
Interviewer: what do you think of Beyoncé

Mariah: she is an amazing person and amazing artist and we love her

Interviewer: and what about jlo

Mariah: I don't know her
by Gabrielle williams July 6, 2016
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"You don't know me" is an incredibly brilliant statement that you can resort to when Mr. Jack Daniels is making it harder for you to say things that make sense.
Cop: Sir, have you been drinking tonight?
Me: You don't know me.
by S4lutDude! December 29, 2010
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A: Hey, dude! 34 that on Photoshop.
B: 34?
A: Yeah, make that steamy.
B: Steamy?
A: Dude, you don't know jack about imaging, don't you?
by Deuces High March 10, 2011
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You don't know anything. You don't know what you are talking about. Similar to squat and diddley. There is also a board game and a movie called "You Don't Know Dick" but the saying is considerably older.
If you had to look this up, you don't know dick.
by terrorint December 14, 2015
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