I think denu has hit it right on the nail. Doms are not supposed to need training, it's supposed to be just part of our wonderful domly nature to know instinctively what to do and what our subs need. Which is, of course, BS. My ex-slave taught me at least as much as I taught her; she had a hundred subtle ways to let me know what she needed without doing anything unsubmissive like asking or telling me.

I'm reminded of the saying that Ginger Rogers did everything Fred Astaire was famous for, but backwards in high heels. Subs may have to do as much teaching as Doms, but without being able to just come out and say it. On the plus side, they're allowed to talk about it.