I don't think we all necessarily have dream guides. I haven't had enough LDs to really know, but one Web site I've been to says that DGs can either appear by chance, or you can consciously create them. (http://www.here-be-dreams.com/lucid/guide.html) Makes sense to me. I figure that if I summon the same dream guide every time I become lucid, eventually he'll start appearing in every dream. If that happened, I think it'd be a lot easier to become lucid. I'd just have to say, "Oh look, it's Cat Stevens. I must be dreaming." Personally, I imagine a dream guide as someone to help keep me calm and realise things about myself that I otherwise wouldn't have figured out. But I don't have any experience with them at all. These are just my speculations.