I have two types of lucid dream

First is the standard. "Oh, wait, this is a dream, cool." And the fun begins.

Second is somewhat similar. I'll realise it's a dream through one way or another and i'll begin to fly. This isn't entirely involuntary as I usually glide around gently to be sure of the dream and it's stability.

What comes next is quite different. I begin to fly in a direction without any control whatsoever. I'll fly right through walls at increasing speeds which can be quite unnerving. Eventually all structure to the world is lost and I'm immersed in darkness. All I can feel is wind blowing past me as I hurtle at an ever increasing speed. Last night the speed became such that my jaw hurt and felt like it was going to rip apart. This felt as real as anything I've felt in waking reality. Rather unsettling to say the least. It is such a hope that someone has felt this too and can give me some insight. At about 50% of my lucid experiences it's beyond the possibility of freak occurance.