What you gotta know 

A turn of phrase originating in Rochester, NY with meanings that vary depending on inflection and context. It can be a question or a statement.

1. A rhetorical question inferring that a person is ignorant or unintelligent, and that they lack knowledge or skill relevant to the situation.

2. A congratulatory phrase inferring that a third party is ignorant or unintelligent, and lacking knowledge or skill relevant to a situation.

1. What you gotta know?

2. What you gotta know!?

What you gotta know by MGRAMM March 16, 2010

trust me, you'll know when

This is a good time to keep your Hilti near. Also, it might be a moment when you have only 20 minutes of oxygen remaining. Your future self came back in time and burned your arm with a cigar just to get your attention, I cannot believe that you don't have this shit down. Where the hell is your Hilti, man!? You're screwed now, that's all I have to say.

<inattentive future self> Oh no! I have flipped the blue switch instead of the red one! I am locked in this airtight room now, and have only 20 minutes of oxygen remaining! If only I had my Hilti power tool, I could simply cut my way out!
<future -> past -> future self> I said to you on that fateful day - keep your Hilti near! Trust me, you'll know when! I even built, at great cost to my own sanity, a Time Door to facilitate implanting this message in your/my consciousness at an opportune moment in my past/your then-present. I see now that you are not the ripcord in my destiny. :(.

trust me, you'll know when by hlprmnky August 8, 2008

You would know 

Something commonly said to someone if they happen to be knowledgeable on something sad, pathetic, or sick.

Brian: Hey Joe, Why do you play computer games all your life?

Joe: What the fuck are you talking about? It only takes an average of 4026 hours 43 minutes and 7 seconds to get all the max levels on runescape.

Brian: You would know... you would know...

Example 2
Conner:There are so many date rape drugs these days People who use them drugs are just sad because they can't get any.

James: Um...rohypnol, ketamine, burundanga, and rohibitril are the only ones commonly used. Besides they only knock someone out for a max of 24 hours... so don't talk shit about date rapists.

Conner: You would know... you would know...

You would know by 99 archerman June 7, 2009

I know you are what you said you are, so what am I? 

The correct way to taunt on playgrounds. Often missaid as "I know you are, you said you are, but what am I?". Mostly by australians. Often shortened to "I know you are but what am I?"

Timmy: "you're a poop head"
Aaron: "I know you are what you said you are, so what am I?"
Timmy: *cries*

I know you are what you said you are, so what am I? by TDYank June 9, 2020

Im so sick of lying you gotta know that 

Naeun from apink in the intro for their song i’m so sick

Person 1 - Im so sick of lying you gotta know that
Person 2 - Ok

Im so sick of lying you gotta know that by Fiftycents January 7, 2023

Reading? I didn't know you could read. 

The sentence Draco Malfoy says to one of his goons (that is actually Harry in disguise) when he see that he is wearing glasses

Person one: "Why are you wearing glasses?"

Person two: "Uh. Reading?"

Person one: "Reading? I didn't know you could read." *Looks kinda impressed*

Reading? I didn't know you could read. by Clara Winters July 17, 2022

I don't know you 

A term used as a greeting, an insult or comeback, a conversation filler (to fill an awkward silence) and a game by adding a word to the sentence. Coined by Cameron, also known as Camen bu in March 2013. Also used as "I don't even know you!," this version is generally when spoken by really white people.

Greeting:
Person 1: Hey Bob, how you been?
Bob: I don't know you!

Insult/Comeback
Person 1: Bob, that was a terrible speech.
Bob: Bro, I don't care what you think, I don't even know you!

Conversation filler (fill an awkward silence)
Person 1: Bob, will you go out with me?
(Awkward Silence)
Bob: I don't know you!

Game
Person 1: Bob, I don't know you!
Bob: I really don't know you!
Person 1: I really don't even know you!
Bob: I really totally don't even know you!
Person 1: You win Bob.

I don't know you by StoogeKebab June 9, 2013