I'm intelligent and confident. I must be an outlier.
Because ignorance is bliss.
Because idiots can't comprehend being "wrong" is an option. Always, stupid people always seem happier in life - not doubting because they can't perceive any deviation to what they have accepted, and unwilling to entertain more complex and depressing notions.
Because intelligent person keep trying to learn new stuff
answer is in your Q.
stupid always tries; intelligent never tries