Hey Cain, I'm no experienced lucid dreamer, but from my few days of trying and from what I've been reading it can take people anywhere from 2 days to develop the ability to anywhere over 8 months... I definitely wouldn't despair over one failed night. You should try saying "I will remember my dreams" or something along those lines out loud several times and then keep repeating the line in your head as you fall asleep. If you find your thoughts drifting try to focus back on that thought.