Usually said in the most common of accents, (mainly those which are widely known as the 'chav' accents) used by several semi-famous people of our time, for example: MC Devvo, MC Dezmo and DJ SpitInYerEye, this phrase is usually used by those who believe they 'genuinely know', only with only a slight colloquial and explicit manner. Nevertheless, the people often using this in the most serious of their own ways are often referred to as pricks.
*Ducks 'swanning around' aimlessly, pecking at the floor looking for some food*
Darren: Oi! Ain't no foods 'round 'ere..!
Darren: I fuckin' KNOW!!
Darren: Yeah, fuckin' showed you dickhead!
Duck: ........ Woof.