know your shit

To know your shit means you're really knowledgeable about a particular topic or field

Lindsay Lohan: I'm telling you the purity of this meth is 61%

Me: Wow, you really know your shit

know your shit by Ededdandeddy January 9, 2016

you don't know shit from your asshole 

To be oblivious or uninformed on a subject you are trying to create a dialogue about.

The fact you think the government faked the moon landing proves you don't know shit from your asshole.

you don't know shit from your asshole by djstickyfing3rz April 3, 2015

know your shithole 

The website 'know your meme' or KYM.

Just used reddit today, time to go to know your shithole to find unfunny memes.

know your shithole by Blank Man 2.0 September 24, 2020