In school, everything its all about remembering facts. It is how good you are in manipulating and accumulating the technique to learn and stocking facts into your brain. The more you are able to remember, the better you will perform.
Therefore, those who fail at school is a person who not literally quite good or interested in remembering those facts. It does not means that they are stupid. Clever people get jobs based on their qualification of the ability to remembering the facts learn at school or college. However, they are not on their desire to succeed.
On the other half, stupid people who does not interested in facts do things on their desire to success.
So, do you noticed how the cleverest people at school are not those who make it in life?