I am personally monogamous. That being said, I have a few friends who are polyamorous. The key is that all people involved need to agree and be on the same page. If you want an open relationship and your significant other does not, your relationship will fail. Polyamory works for some people, but for many people, it is a paradigm shift that they can't make. It wouldn't work for me, but it works very well for my friends in those relationships.
From what I understand, and I read this on a post somewhere that I, unfortunately, can't find right now, the concept behind it is you have an apple and an orange. Sometimes, you really want an apple, and sometimes you really want an orange. But you can't necessarily compare the two, because they're so different, and fulfill different things. The apple can't fulfill what the orange can, and the orange cannot fulfill what the apple can.
If that's a path you want to take, my recommendation is to do so with a partner that wants that sort of life. It's not fair to simply expect that it will be okay with someone. There is nothing inherently wrong with someone being monogamous, just as there is nothing inherently wrong with someone being polyamorous. It's just expectations that you need to be on the same page for.
I hope this helps. Best of luck.