ETA: I had not seen the other brain-related posts just above while writing this one. And mine is definitely not The Brain From Planet Arous.
Speaking of quotes …
I’m not remembering the movie’s name, but there was one of those late 1950s “classics” involving monsters that were disembodied life-sized human-like brains trailing a spinal cord & some spinal nerves and (IIRC) with eyeballs somehow hanging just below the brow of the cerebrum. And they could fly. Or at least jump out at victims from their hiding places. The humans called the monsters “ghouls”. Somehow the ghouls killed whoever they jumped onto. Or else transformed the human into a new ghoul; I forget which. Either way it was Not a Good Thing to get jumped by a ghoul.
Of course it takes place in a desert small town complete w earnest good guy but not too bright Sheriff, attractive sweetheart Nell, a scientist from the nearby military base come to investigate, and all the oh-so-hokey rest.
A one point the scientist is using technobabble to explain to the sheriff, the sweetheart, and a few generic townsfolks how to defeat these things. At which point the sheriff butts in: “So you mean, doctor, that if we kill the brain we kill the ghoul?” He replies something like “Yes, that’s pretty much it.”
My thought as an ~8-yo at the time: Hell, the whole thing is a brain; there’s not much else to kill. Now armed with this miraculous martial maneuver (and a bunch of shotguns) the townsfolk proceed to splatter the marauding mental meat menace all over the landscape.
But ever since, when I need a “no shit Sherlock!” comment it’s “If we kill the brain we kill the ghoul!”