And I do mean that seriously. Have you ever read the DRESDEN FILES by Jim Butcher? I'm on book three, and I still know very little about his world and even his magic system. He explains things only at the very last minute, once they absolutely need to be explained.
That, inconstant magic rules and cussing are the reasons I've never made it past book four. But I'm getting off topic.
I've always said just write the first draft and don't worry about info dumping. Those things can be cleaned up in the second draft. One person I asked told me that he wrote his whole first draft without explaining anything to see if alpha readers could figure it out on their own, or if he need to go in and provide information. I think that is a good system too.