It depends.
I.e., my sub disposition is dependent, responsive: relational.
i cannot relate to D/s scenarios that are dependent on rules vs relationship. E.g., i go on a kink site and a self identified "dom," who i have never met or have little to no relationship with, contacts me and starts making demands based on just the notion that because he calls himself "dom" or i say i'm "sub" that he can automatically dom me and i will submit because it's just an assumed rule that sub's submit, not matter what. And i have seen A LOT of guys with this notion, on both sides of the fence, to the point that i shy away from using the word "sub" to avoid the presumption.
For me, the thrill of a D/s dynamic is how deeply it can facilitate bonding and connectedness in a relationship. i see a Dom as the artist and the sub as the clay or canvas (the analogy helps me articulate, even though it's not perfect). To me, an artist has to know and understand the 'material' they are working with and how to work it in order to achieve the results they desire. That knowledge and understanding is realized and developed in ongoing practice.
i have stayed in a sub role for an extended period of time, but it wasn't just me submitting, it was me responding to a Dom who loved, enjoyed and knew how to elicit my submission, both in action and emotional/mental disposition.