Is this a certainty? Depending on how we define the dawn of "love," it seems at least vaguely plausible that it occurred after the first human consumption of coca. Of course if we're specifically talking about isolated cocaine then you're correct for sure.
Coca is a "new world" plant, growing only in the Andes mountains. As best we can tell, there've only been homo sapiens sapiens on that continent for a few tens of thousands of years, at the outside. The hormonal basis for the phenomenon we call "love" is without doubt older than that.
Is this a certainty? Depending on how we define the dawn of "love," it seems at least vaguely plausible that it occurred after the first human consumption of coca. Of course if we're specifically talking about isolated cocaine then you're correct for sure.