The practice of meditation can take as much conviction as lucid dreaming techniques.
A quite mind does not come naturally. You have to train it. It wants to interrupt a tranquil state with a thought.

What you can try to do as acknowledge the thought but don't think of it as any more than just ...(thought) Don't react to it or think about it. Just acknowledge the thought.
Your mind like thought. Once you maintain a level of mundane thought processes your mind begins to give in and this is where the meditative state can be recognized.

For myself I have to not be TOO tired, but also I can't be TOO awake. Much like the WILD tech. or the HIT tech. A happy medium and balance.