I don't have any idea about this. But I guess Xanth is right. There is a point is Xanth's reply.
Quote from: Xanth on May 05, 2013, 15:10:35
This is why when we practice reality checks while awake, it's VERY IMPORTANT to stop everything you're doing and give the check your 100% undivided attention, so that this action carries over into your sleep time and you'll also give it your 100% undivided attention. As long as you're doing that, it can't fail.