Often I wake up in the middle of the night, remember my dream and remember that i want to become lucid. I say to myself "When i fall asleep i will be dreaming, in my dream i will *insert desire*" I quickly fall asleep. I will i often get my wish and i am lucid for a little bit (able to carry out a few small desires). then however i lose lucidity quickly and resume a "normal" dream. How to i prevent that.