How do you know you're having a bad night?

When you don't have a nightmare, but have a dream about having a nightmare. A dream within a dream dream.

How do you know you're having a really bad night?

When the thing that jolts you up in the middle of the night, in full-panic mode is because you think you're hearing the click-click-clicking of the aliens from Signs.

How do you know that you're mind doesn't work like most people's mind?

When the thing you say to yourself immediately upon waking up in a cold sweat to calm yourself down is that not only are you not being invaded by aliens, but that Signs was a totally over-wrought, over-dramatic movie and totally not worth having a nightmare over.