Education is so important, but it's not only found in schools. You don't only learn when you take a class, tests, and get a diploma to say that you learned something.
I don't have a highschool diploma. I'm three credits short, all math. While I'm working on trying to change that (which, right now, is mostly trying to find time to change that), I can tell you that I'm not stupid. I'm not uneducated. I'm not saying I'm a genius, but I can still honestly say that I'm smart.
Do you know how to play an instrument? That's not just skill, but it takes intelligent. You have to know about how the instrument works to know how to play it. I don't know about that.
Do you know about sports? There are so many rules, regulations, plays, even different teams and players to know about. I know next to nothing about sports.
Do you know about computers? All the programs, how to fix minor issues, little keyboard shortcuts that many people don't know exist. I know multiple people who have even built their own computers. Not my strong suit at all.
Do you know how to handle people? Customer service is one of the most difficult jobs that you can have. It doesn't take much paper-education, but it takes people skills and knowledge on how to handle situations, plus being able to think on your feet incredibly fast so that you don't get screamed at by somebody. (No, for real, I was screamed at and told my store would fail because I wouldn't accept a pair of shoes back that the lady completely destroyed.)
Do you know about fashion? Just because it's clothes/shoes, doesn't mean it makes it useless knowledge. Somebody has to be out there designing the next big trend and making new things that everyone likes.
I don't know much about anything I listed so far, but let me tell you what I personally know about.
I know a lot about medical and mental illness, especially considering I've never studied it outside of highschool level. I know about different signs when somebody is on drugs and which drugs they're on. I know body language. I know how to rescue a lot of types of animals, but cats are my strong suit. I know about hair and how to take care of it, especially when you dye it often. I know more about rental/leasing than the lady who works in my apartment complex lobby.
You know things. You know so much. Your brain is a collection of thoughts and ideas and facts. The one thing that you don't know, is how brilliant you actually are.