Like me, you were probably exposed, like most of us, to the ideas in Carl Sagan's "The Dragons of Eden" and "Broca's Brain"

The triune brain hypothesis became familiar to a broad popular audience through Carl Sagan's Pulitzer prize winning 1977 book The Dragons of Eden.

https://en.wikipedia.org/wiki/The_Dragons_of_Eden

https://en.wikipedia.org/wiki/Broca%27s_Brain

The other mythical meme of note from those days is that we only use 10% of our brain.

The article sets up a bit of a straw man (or maybe a motte-and-bailey) I think, because it says "all mammal brains (and most likely, all vertebrate brains as well) are built from a single manufacturing plan using the same kinds of neurons."; but I'm not sure that really refutes the notion that most of us have when we think of the lizard brain. Ontology doesn't recapitulate phylogeny, but we do have a cerebellum, and our actions and reactions happen along a broad spectrum of temporal control and conscious awareness.

I thought the "lizard brain" was the part of our nervous system that would respond before the actual brain had time to process. Like I've heard we'll pull our hand away from a hot pan before we feel pain.

Now I both don't know if I've misunderstood peoples references, and have no idea if my version of a lizard brain does exist.