My earliest fantasies, when I was so young that sex was a thing grownups did to make babies, ranged easily between top and bottom situations. When I was a teenager it largely depended on my mood. If I was feeling comfortable with life, I could enjoy a fantasy of being abused and humilated by a bunch of girls: if the world was treating me bad, I wanted to torture and degrade some imaginary victim(s). I often liked turnabout scenes where the victim took over and punished the abuser, sometimes running through several reversals of roles in a feature-length daydream.
But when I started to experiment with bondage games with friends, I found that most of them couldn't grok what I wanted done to me, so I got used to taking charge and being the binder/torturer/slavedriver. That still seems to work best for me, but it depends on the other partner.