I've noticed that whenever I'm in a lucid dream, a lot of times I will check reality and still think that I am awake, so that really bites, I hate when that happened, so many times, in fact that I found out the following "rule'" :

Unless you are unstable in waking life because you can't even tell whether you are really awake or not...this happens to me a lot, but I'm just really lucid even though in the back of my mind I know I'm truly awake...

If you ever are unsure of whether or not you are dreaming or wake...

for example, you are in a very lucid dream, you hit something and it hurts, it looks like it does in reality, maybe it's a False Awakening, but what I am going to tell you will really help...

If you ever doubt your reality checks and tell yourself "I'm awake...." when you are dreaming..., THEN YOU ARE TRULY ASLEEP/DREAMING!!!!!

Repeat this to yourself daily and before you go to sleep at night, like a mantra or affirmation....

(It won't work for the reason already stated, if you simply, also, have something like OCD or split personality disorder...)

I tell you this because it has worked for me, I realized that i missed so many 'lucid opportunities' that i realized the only time I questioned it was when i was truly alseep.....

I hope this makes sense....It works wonders!