I did things backwards. I didn't know the term "polyamory" until after I was polyamorous. I'd always had a semi-open relationship with my husband since we first started dating, usually FWB's, and I had some very close friendships, but I never really thought about the logistics regarding being in love with more than one person at a time until it happened. So, I guess I "knew" a couple of years ago, but at the same time I still don't "know" if I consider myself poly in the sense that I don't know if I would look for this relationship structure if I didn't have it. I've never been the kind of person who looks for "The One" or now "The Two" or "The Three" or whatever. Relationships happen, and you have to decide how much work and effort you're willing to put in based on how much you want that person in your life, not how much you want a certain role filled.
Pan Female, Hinge in a V between my mono (straight) husband, Monochrome and my poly (pan) partner, ThatGuyInBlack