Thought to have originated from the "That 70's Show" quote "...is that a thing?". Highschooler Joshua MacLatchie coined this phrase to mean you are absolutely sure that isn't even a real thing.
This also predates Seinfeld because fuck physics.
This also predates Seinfeld because fuck physics.
Ex:
Zach: I totally dunked my balls in her ass last night, shit was so cash.
Shim-sham: That's not even a thing.
Zach: I totally dunked my balls in her ass last night, shit was so cash.
Shim-sham: That's not even a thing.
by 100%RealFactChecker July 8, 2014