I'm surprised to be writing this. Before I met my current partner, I really thought monogamy was a big mistake. Oh, I'd try it, usually because monogamy was a precondition for continuing having sex with someone I was attracted to. But after that first flush wore off I'd start feeling like something was broken. As if that insane passion of the first days of a relationship was the natural state and should last forever, and if it went away there was something wrong, and nothing would ever be good again. That, and a dozen other reasons both rational and irrational would lead me to ending relationships, usually as painfully and selfishly as possible.
In retrospect, I probably should have embraced the idea of open relationships, and been continually honest with my partners that there were, or would be, other people. I think I thought if I did that I'd never get laid again. There's also the idea that you're a bad person if you want that. We're either supposed to be celibate, or with a single partner in a monogamous relationship. So I kept on trying to be monogamous, failing, lying about it. It had it's fun points, but it wasn't good, and it wasn't healthy, and it wound up hurting people I cared about.
But then one day I met someone who I cared about more than myself, someone who I feared losing more than I feared missing an opportunity for passion with another woman. With her, monogamy is easy. I've discovered something I never stuck around long enough to learn before. Yes, that crazy passion of the early days of a relationship goes away, but better things take its place if you work at it, and it's worth the work. I also discovered that there's a whole lot of extra hassle, baggage, headache and heartache that goes along with those early days of a relationship and I'm so happy that I don't have to deal with all that, ever again.