Glass Joe the Champ said:
It's the ego that makes the human believe that, that's why everybody think they are over average.
Personally I'm playing dumb, and I'm really good in school and I'm really "street smart" but if you're asking me a test on school level can't tell you if you're smart or dumb, it's life experience, how you act in different situations how you handle life, the truth and pure chaos.
Being skilled on a educated level is intelligence but not in the same way as knowing how to think freely, come up with new ideas and inventions and being a really wise man with a lot of experience. A educated man can still be blind and dumb if he don't know how to think outside the frames, by free will and is possibly manipulated by a system made for controlling.
A man who lives in the forest like a savage nearly doesn't even know how to count to ten (probably) and is probably technically retarded on a educated scale but he knows how to solve every dilemma he comes across and got a real skill for making up new functions on different objects and surviving.
So if you only have one of the sides you're dumb, you gotta have both to be able to function properly in the regular society in most countries, but I still think the educated knowledge is less needed than the common knowledge and basic intelligence if i need to pick one of them.
Do you see what I'm trying to say?