Being aware doesn't always go hand in hand with remembrance. You may vaguely recall that you were lucid during a dream, but the content may escape you. Having taught many workshops, I often found that understanding this concept was the most difficult stumbling block. So, I cannot stress enough the fact that being aware in a dream, does not automatically mean you remember it. For those who have never or rarely produced lucid dreams, learning the technique is akin to developing any skill.
Some people learn new skills easily, others it takes time and discipline.
It is not unlike learning a language. When you were first born, you didn't come into the world speaking fluently. It took listening, practice, and probably some very shaky attempts before you spoke fluently. There are many techniques that have been developed to learn lucid dreaming, and many are quite good. I tell my students to try a few methods, and find the one they feel will work best for them, and stick with it.