This is what you say after you punch and/or kick a guy in the balls. This is a good revenge to use on douchebags. Here's what you do:

Knock on douchebag's door.

When douchebag answers, come at him like a spider monkey- a deranged, rabid spider monkey.

Punch/kick him right in the nuts.

As he writhes on the floor and cries, "Whhhhyyyy??!?!?!", You point at him and yell very scarily, "YOU KNOW WHY!!"

And he will know why.

Revenge accomplished!
How to correctly carry out a "you know why."

Dave (answers door): Oh, hi..
(Sara, crazy eyes and all, punches Dave in the nutsack)
Dave (falling to the floor): WWWWWHYY?
Sara: YOU KNOW WHY!
by ,fknkd April 25, 2010
Get the you know why. mug.
An exaggerated statement usually following a junk punch; including a gesture of an angry pointing of the finger and an evil eye.
*Knock on door*
*Douchebag answers*
DB: ..You!
*Junk puncher punches junk*
DB falls to his knees: WHY?!
JP: You know why.
by pinkdaisy4 February 10, 2009
Get the You know why. mug.
often said when someone does or says something stereotypically Maori, such as stealing or going to KFC.
you know why... its because your Maori.
Nathan: bro i got me a mean feed at kfc last night
Josh: you know why...
Get the you know why... mug.
Often accompanied by someone playing a few seconds of the song titled "Sicko Mode" by Travis Scott, they are the cursed words every single McDonald’s employee had to listen to day in and day out every single day between September 8th and October 4th 2020 when excited customers came to order the meal at their local McDonald’s, some even visiting several as they reportedly had shortages on common items found in the meal due to the popularity of the promotion. If you’d like to see some of this madness for yourself, search up "you know why I’m here" on YouTube. (Without the quotation marks.)
McDonald’s employee: Hi, welcome to McDonald’s can I take your order?

Customer: You know why I’m here. (plays Sicko Mode)

Employee: *sighs internally* You want some Sprite with that?

Customer: Yeah.
by Mikkebak August 10, 2021
Get the You know why I’m here. mug.
Common phrase heard from Norman "Nick". He says this whenever he wants to place emphasis on something that he just said. Usually, he'll say this after he says something that he considers to be bold and will want to flex what he just did.
Norman "Nick":" I just read this entire book in one night"
Henry: "Ok?"
Norman "Nick": "You know why I said that right?"
**the whole time, Norman “Nick” was trying to flex that he read a book and did something productive**
by TurnM3Up April 16, 2020
Get the you know why I said that right? mug.