My husband and I came to poly through a long, hard and confusing road. We were both raised to believe that you were supposed to find "the one", settle down and have kids, but all after you finished schooling. We met freshman year of college, clicked right away, and both started thinking of our life together once we graduated (we were both VERY naive).
Things didn't go as planned. An ex-boyfriend of mine showed up, who I still had feelings for. I wanted to give it another shot with him, but I didn't want to lose my "long-term boyfriend". We remained friends while I was dating my ex, and eventually got back together. Later on, he started having feelings for one of our female friends, and actually asked me if I would be upset if he pursued her. I gave the go-ahead, but unfortunately, we almost ruined our friendship with her because we were careless, and didn't really discuss expectations. It became clear that she wanted an exclusive, monogamous relationship with him, and blamed me for "holding him back". We eventually resolved everything and she and I even became roommates a couple years later, but there was a lot of bad communication and heartache in between.
Even when we got married, we thought, "Okay, now we're going to stop this and settle down and be 'normal' people". But many of our friendships tend to evolve into infatuations or very deep caring relationships, and it seemed unfair to limit each others connections.
I gave up asking why we weren't "normal". My husband and I trust each other very deeply, and I know that is an extremely important part of our relationship. I think many people without a strong level of trust in their own relationships are inherently suspicious of ours. I'm still coming to terms with whom in my life I do and don't share my relationship status.