What the Fallacy?!
Personal Incredulity
The Fallacy
Saying that because one finds something difficult to understand that it's therefore not true.
Why it's wrong
Complex subjects like biological evolution through natural selection require some amount of understanding before one is able to make an informed judgement about the subject at hand; this fallacy is usually used in place of that understanding.
Example
Jerry looked at the diagram of the complex microchip and declared that since he couldn't possibly understand how sand could be taught to do math, computers must run on magic.