Face it, you lie because it's sometimes easier than telling the truth, or you don't want someone else to know the truth. If there ever comes a day when every word say say to another is some sort of lie or even just a small deviance from the truth, be prepared for your dream that night.
For he will come. And you will not be able to lie to him.
That night you shall dream of being chained to a board. Lying flat on your back, unable to move, the only things you will be able to see will be a tray with all sizes of knives on it. Ranging from the most precise surgical scalpels to the largest hacksaws. A single light will dangle from the ceiling, its light barely reaching the edges of a very dark room.
And there will be a man sitting on a stool. You won't be able to see his face, because he will be just out of the light. He is the Lie Detector, DO NOT lie to him.
His task is simple; all he does is ask you 100 questions. He will wait patiently for any amount of time for an answer, but if you wait too long, he'll say, "Time's up, we'll continue this tomorrow." And you shall have that dream again, starting exactly where you left off.
His first question is always the same, and if you answer truthfully, he's very polite. Just tell him what you name is when he asks for it, and he'll be nice. However, if you lie to him on something as simple as your name, he will lose any sign of pleasantness and his image will haunt your waking hours. The questions after are fairly unique to the individual, some being yes and no questions, other being more difficult.
100 questions should be easy to answer truthfully, but if however you still decide to be deceitful, for every wrong answer you give, he will take a blade from the tray, and cut you. Slowly, deliberately, and as painfully as possible. It starts off really nothing, mere paper cuts on the webs in between your fingers, but working up to the carving out of your eyes to the removal of "certain unnecessary appendages."
After he's finished questioning you, he will leave. If you were good enough to answer every question in truth, you will wake up immediately in nice sunshine. However, the more cuts you have accumulated, the longer you must stay in the room, bleeding out while the sound of a blade sharpening is in the other room. The longer you must stay in the room, the louder the noise gets, and the darker it is when you finally wake up. Do not be surprised to find the scars of the cuts still on you. They won't heal.
If you've lied on every question, he will shake his head and leave the room. You will be able to hear the sound of the sharpening growing louder and louder, until it's sound nearly drives you insane. That's when the man will finally return. You won't see him, your eyes most likey having long been cut out, but you will hear him. And he will start to slice you. In quick, precise strokes, faster than thought, he will cut off anything else that remains of your arms and legs. And finally, he will start on your spine, cutting off sections of your torso piece by piece. Obviously you won't survive the procedure, and beware, if you die in this dream, you really will die in real life.