i agree Ozme52.. To please your Dom/me is you main goal as a sub.. If he wants you to top someone .. including him/her.. you do it .. out of love, the want and need to please him/her and the want to give ..
To serve his/her wishes is to please him/her..and the main part of being a sub is to please him/her .. whether you may like it or not.. Unless it is an agreement that you would never have to top that was previously set in limits then to not do it would be letting your Dom/me down i would think .. an uncompleted task.. Knowing i had let him/her down and not completing my task.. i would feel i failed him/her and i would feel disappointed in myself..
and you are right Ozme you won't feel that Dom/me side until you have someone that submits to you..
Just my opinion
hugs
snow