> I can assure you nothing of what remains in my brain was shaped by society
> I lack the words to stress how much this is intimate and personal. Now to each his own brain, some people might have very few emotional attachment, I'm not like this
So are you a robot then? Wherever you are from, your mind is a product of your influences and local culture and customs, just as much as it is also a product of your schooling and your family life. Given that we humans just absolutely love to meddle in the love lives of others, I can promise you that some of that cultural training includes guidance on how to structure your romantic relationships, and it almost certainly proscribes one man and one woman.
Unless you have spent a considerable amount of time examining these beliefs and have specifically chosen to reject the ones that your society has given you, I would argue that your brain is very much not your own in that sense.
If the opposite were true then things like propaganda would have a much harder time existing. We would have a perfect, rational world society that I dearly wish existed. Appeals to emotion would fall on deaf ears! How amazing that would be!
Instead we have entire countries full of people that live or die because of "cultural differences" aka the shit that society pollutes your mind with. One might argue that we are watching that play out with Ukraine vs Russia right now.
> Stop, you have no idea about my personal life.
You told me how you feel, so I do in fact have a small tidbit of information on your personal life