Yep, exactly- In all the years I've been wandering around kinky forums & talking to people, I've noticed that we worry far too much about what's what & who's who.
As sisterhoney pointed out, it can & often is taken to extremes.
Sure there's nothing wrong with seeing yourself as a slave/sub/someone's property or whatever, but IMO it makes sense to keep in the back of your mind that these are personal definitions. Some will agree & some won't.
Ultimately, all any D/s relationship is, is a consensual agreement between two people. Even that agreement can change from day to day.
What's important IMO, is to concentrate on your own relationship first & foremost- get that right & put the effort in before worrying about who & what you are.
D/s can be pretty darn amazing, but let's not forget it should be fun- not an agonising search to 'fit in' as the straight world can be.