Is there a word for someone who wants to appear learned or knowledgeable but has no clue he isn't?
I think it's primarily a British usage, but...
pseud - a person who tries to seem to have detailed knowledge or excellent judgment of a subject, especially in art, literature, music, etc.
...usually identifies someone who doesn't actually know what they claim to know.
Wheeler had walked into two Pittsburgh banks and attempted to rob them in broad daylight. What made the case peculiar is that he made no visible attempt at disguise. The surveillance tapes were key to his arrest. There he is with a gun, standing in front of a teller demanding money. Yet, when arrested, Wheeler was completely disbelieving. “But I wore the juice,” he said. Apparently, he was under the deeply misguided impression that rubbing one’s face with lemon juice rendered it invisible to video cameras.
Also known as the "Dunning-Kruger effect" - http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
The Dunning–Kruger effect is a cognitive bias wherein unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than is accurate. This bias is attributed to a metacognitive inability of the unskilled to recognize their ineptitude. Conversely, highly skilled individuals tend to underestimate their relative competence, erroneously assuming that tasks which are easy for them are also easy for others.
"Self-proclaimed" is often used to describe someone who thinks they can do something, but actually can't. For example, a "self-proclaimed therapist" might believe that he has the necessary knowledge and abilities to be a therapist, but he really doesn't.
Self righteous person who maintains his / her position and ignores the facts. One who jumps to conclusions without first performing the research needed to arrive at a balanced decision. I agree with the above answers as well. they are interesting.