These are the scopes of knowing if you are stupid.

1. you know your stupid about some things.
2. there are things you don't know about, or that you are stupid about those things. but you can still conceive about these things as not known and that you may be stupid about them.
3. tailgaters, they don't know they are stupid and they don't have the ability to know they are stupid. also these are the people that took life science instead of physics in high school.