Easy to Believe.

Ever find yourself accidentally cutting people off when you have something you really want to say? Because you really want the other to finish speaking, you'll easily believe that he is actually done speaking when he makes a small pause. However, the duration of a pause that will convince you that he is done will be much smaller than when you aren't so eager to speak.

In general, the more you want something to be true, the easier it is for you to believe that it is.

That may also be why there are so many gamblers, smokers, and religions. That's also may be why crystal ball readers give positive readings more often than not.