Nightmare = Lucid dream??

All my “natural” LDs prior to learning about lucid dreaming have been due to nightmares. At the pinnacle of fear (e.g., a monster is chasing me), I become lucid. Of course at the time I didn’t know I could control the dream and whatnot so the time spent lucid was used to try and wake myself up.

Recently I have had a few nightmares, but I don’t mind them. I fly away from the nightmare and into a regular lucid dream.

I could only speculate as to what the scientific reason for this is. Has anyone else experienced something similar?