Yeah, read it in another comment. Why do you think doing calculations in your head is brute-forcing? Many people can do it flawlessly, without even knowing of these "tricks". They just know. Is that brute-force?
Your original comment completely missed the point of what it was replying to, you phrased it like you were correcting them but you were actually in agreement and didn't seem to realize it. They tried to clarify when you asked and when you responded you assumed they had the opposite viewpoint from what they actually have.
> how is calculating it in your own head brute-force
Doing this calculation in your head is not brute force, which was their entire point. Their math question was an example of why the brain isn't brute-forcing solutions, replying to this:
> What makes you think your brain isn't also brute forcing potential solutions subconciously and only surfacing the useful results?