Well sometimes, things just aren't as simple as they seem. It is easier to believe what is easiest to believe.
Take M and Ms...melt in your mouth, not in your hand. Now, I have not fully tested this statement..reason being, I could potentially end up with a handful of crunchy sticky chocolate nuts...aggro.
Hence, it is easier to believe that they won't melt in my hand.
Also, to find out the real truth, that M and Ms will infact, melt in my hand, would mean that I could no longer use the line "Hey baby. I'm like M n M's...I want to melt in your mouth, not in your hand"
You see?