What's a sub? Confused

What's a sub? Is it a piece of furniture?

If that's the case I don't want to be one...

I understand the whole concept of obeying, but there's a difference between obeying and feeling stamped on. I can't obey when I feel you demand it just to put your plans first and mine last. A legitimate excuse to put me in second place. Why should your plans be upheld and mine be crushed? Because you're Dom and you get to decide and demand obedience. It is your right as a Dom. But does this mean I always have to settle for second place? Maybe a sub's place is always second place. Does this mean I have to say "yes sir" and obey even if I feel crushed? I don't wanna feel crushed. Maybe I wanna be equal in some things. Maybe if I plan something 2 days ahead you don't get to cancel it because you felt like doing something else. I don't wanna take it and smile and say "yes sir" and be enthusiastic about whatever other plans you have. If that's what it takes to be sub then maybe I'm not a sub.

I'm not a piece of furniture, that i know for sure