Sexuality tends to be like a rushing stream, changing in relation to the external conditions. What gets you off one day, might not work for you the next. Sure, some of us might perfer one particular approach over the other (Top or Bottom), that is a chosen mode of our expression. Even in that defined approach, there can be alot of flexibility, as to just how, or what we want of the experiance (rough, loving, kinky, vanilla etc...). I guess it's akin to flavours;and some might not have very developed taste buds, compaired with another more demanding gourmet (then again, some perfer to stay in the kitchen and cook).