:notworthy
Correct, and very well explained (you big spoil sport

)
I can see I need to try a little bit harder. Are you familiar with the old classic riddle of two doors and two guards?
One door leads to safety, and the other to certain doom, and you don't know which door is which.
Each door has a guard in front of it. One guard ALWAYS lies, and the other ALWAYS tells the truth, but you don't know which guard is in front of which door.
You are allowed to ask ONE of the guards ONE question only .. and it cant be a great big long run on question with lots of 'and' . Note: The guards themselves know which door is safe and which is dangerous.
By asking this
one question, you still wont know which guard is the truth teller and which guard lies, but you WILL know which door leads to safety.
So what is the one question you should ask?
Hope that one causes you a little more head-scratching time

And for the record, the most common solution to the above scenario is to ask one of the guards, "If I asked you if the door you're guarding leads to where I want to go, would you say Yes?" If he says Yes, then you go through his door, while you go through the other door if he says No. This is because his answer to this question doesn't depend on which guard he is. Say he says Yes to the question. If he's telling the truth, then he would say that the door leads to where you're going, and thus, the door will lead to where you're going. If he's lying, then he'll have to lie about whether he'd say Yes to the question (which, in this case, he would not say Yes if asked if the door led to where you're going, and would in fact say No) and, thus, is forced to give the correct answer to where the door goes. Of course, this requires that both guards know where you are going, and that neither of them considers "Your doom" a place
Sorry for derailing the Op Illusion thread with a couple of riddles... so I included one to keep it on track too. Which did you see first in the image... a rabbit looking to the right... or a duck looking to the left?