I had given up, thinking that I was one of those folks for whom it was impossible.
So I was pleasantly startled when I actually found myself having a lucid dream during the third week of the course. I used the first hypnagogic affirmation (the next time I'm dreaming, I know that I'm dreaming) and was absolutely primed and determined. I am a spiritual person with a scientific/medical background, so when I found myself in my dream, it seems I first wanted to explore the landscape, using my dreamer as my guide. So I didn't impose any demands, but just let the dream flow on its own, learning and seeing along the way. It was in many ways a life review, with family members and loved ones guiding me.
I am now awaiting a second lucid dream, and more to follow, when I will start to incorporate the spiritual and more advanced techniques that were covered in the course. Knowing that I am capable of having lucid dreams was a huge breakthrough for me and has definitely increased my self-confidence.