Lack minded individual
A lack minded individual is like a group of brain-dead morons who all agree on how dumb they are.
My cousin and his friends are all lack minded individuals. They all think they're the smartest people on Earth and they're not even paying attention.
My teacher called the whole class lack minded individuals because we all forgot our homework and thought it was funny.
My mom and her friends are lack minded individuals. They all think they’re the best at baking, even though they burn everything.