I am polyamorous and have always been so, but didn't have a term for it until about 1999. I was born in 1955, so do the math.
I lived mono for approx 30 years, as one is supposed to do. I was more or less miserable, romance-wise, all those years, tho the h was a great guy in many ways. (We tried poly in 1999-2000 but gave it up, it was too hard given our former dynamics.)
I always had a roving eye, always got crushes on friends, neighbors, even celebrities. And h was always jealous. Even of the celebrities!
Once we finally separated, I damn well went looking for lovers! I didn't and don't have time to just let them find me, wasn't very likely in my circle of mono, married, hetero friends. I went looking on ok cupid, found a gf, kept dating, had lots of fun, tons of laughs and romance and sex with lots of not quite right people, finally found a real bf over a year ago and have not regretted a thing.
The 3 of us are in a V, me as hinge. We do not struggle with jealousy or time management in more than a fleeting way. Things are usually settled with an hour's conversation, if even that. Mostly we just live and love and get on with our lives. (We're all pretty good at stating our needs and desires and being honest and forthright and using I statements, and we aren't needy clingy, we all like alone time.)
And I am super happy! Took me long enough to become the authentic Magdlyn.