I've met people who claim both ways of coming into the fold. Curiosity is powerful and in modern society almost anything is available so it's easy to be exposed to it. Some people are both Dominant and submissive. They are commonly called a switch. Some are only submissive with certain people. Some are only Dominant with certain people. There are so hard and fast rules. It's what you feel like. I encourage you to explore and experiment. That's the fun. Do it safely, and with some planning up front. SSC Safe, Sane, Consensual.