If you went to any type of schooling, chances are you are highly educated. Curriculums are mostly standardized, so it's not until you get to higher education where you can customize your classes and education plan that the levels of education really become apparent. There are so many ways to tell how educated someone is other than just asking them a bunch of questions about things they learned 20 years ago.
If you made it to college, and through college, then you are educated enough to be granted a higher education degree. But college isn't for everyone. Maybe you educated yourself through independent research and watching other people do things. Home-schooling is also another form of education to which people really take. Many times, you can learn at your own pace and work harder at things you don't understand in order to grasp the concept better.
General knowledge is also very different from niche knowledge. You can probably still recite the preamble to the Constitution, but unless you are a history major, or a law student, the details and the ins and outs of the Constitution are probably foreign to you. That doesn't mean you aren't educated, it just means you haven't chosen a specific track in which to gain more knowledge. If you're curious about what percent educated you are, take this quiz!