Worst nightmare!!!

Its been a long time since I've had a nightmare. But there is one I will have as a recurring nightmare at times. But there is one dream that probably wouldn't scare most people, but scares me. I dream that I am rock climbing with my friends (this is something I have never done) and we are really high. Something will happen and I will fall from the highest point...I'll usually wake up before I hit the ground, but there have been times where a friend in my dream will fall and my bed will actually shake when that person hits the ground. Its really strange and disturbing.