If it was a lucid dream, why didn't you just wake up?
As for me, I have lucid dreams once a month probably. Normally I just end up dreaming about being a military commander, or a Pokemon trainer, or whatever is on my mind at the time. You actually can engage different parts of your brain to help you solve problems in a different manner. I use lucid dreaming to do calculations and solve physics problems or just normal ones. I also remember nearly all my dreams witch makes nightmares suck.
I actually prefer to just sleep and not dream and then just daydream the next day at school.