In my opinion, the question should be, who is the most gullible?
For every person who tell lies, 90% of the people around them know it is a lie. Most people believe in lies becos they WANT to believe in it, they NEED to believe in it so as to make their world a little better.
When you see the truth, no matter how the person twist and turn until black becomes white, your mind will tell you it doesn't mean sense. Yes means yes and it can be proven, otherwise with WL, there is no grey area.