I'm 17 now, and have a LD about once a week--in some cases more, some cases less. Just depends, but my average is once a week. My first LD was back when I was a kid, before I even learned what a LD was let alone knew I could take control of my dreams.

While I do like your theory (it certainly makes sense to me), I don't think it applies to everyone, as you mentioned in the second chunk of your post. Like I said, I'm a frequent lucid dreamer. However, I'm also a very logical-thinking teen--so maybe that has something to do with it? Like yourself, I'd consider myself to be more mentally mature than my peers (it's rather hard to word without sounding arrogant or anything, but whatever).

Another exception to your theory is kids that are able to LD. As they have reached adolescence let alone passed it, their frontal lobe wouldn't be nearly as developed, and thus their logic is under-developed (which makes sense--talk to a kid about things, and they'll justify things in what seem like completely irrational reasons to adults, but make perfect sense to kids).

So, while I do like your theory, I don't believe that the frontal lobe's development has anything to do with the ability to LD...but maybe I'm wrong. I almost hope that I'm wrong, because then that'll mean LDing would get easier as I pass into adulthood...who knows.