I cannot imagine “knowing” as much as you, when it seems to me that the more I study, the more facets, nuances, and subtleties I uncover. Trying to fathom the idea that there are precisely and only two of every single thing on earth - genders, political parties, black or white, good or bad, even day vs. night - when what I see is a rainbow of spectral complexity, for example a very cloudy (rainy?) day or a bright moonlit night… is too constraining, nay actually heart-rending for me to do for long. You may feel free to keep your eyes squeezed shut if you must, but I promise you that if you peek out of them, you will see wonders abounding!
Anyway you are correct - it is both sides(-er-ism). But also… it is not?
“I wasted time, and now doth time waste me; for now hath time made me his numbering clock: my thoughts are minutes; and with sighs they jar their watches on unto mine eyes, the outward watch, the heart, where sorrow lies.”