As the spouse of a retired special needs teacher of 31 years I can say with some confidence there is no way you would have been viewed as "average," nitwit.
Here's the thing about the education system nobody wants to talk about out in the open. Kids come to school with an IQ that is virtually impossible to improve on. It's what happens at the margins that makes a difference. Like parent involvement and support, the home environment the kid comes from, the types of other kids in the school, is the kid hungry when he gets to school, has he slept in his own bed or in a motel room? Teachers get both too much credit for high achieving schools and too much blame for low ones. Can a teacher's skills change how much a kid learns in a given year? Yes. Is a teacher's skill the most important element in a kid's performance? Not even close.
The reason some kids from some ethnic backgrounds consistently do well is because they come from a culture that values education very highly. The kids who do poorly tend to come from families who do not share that value of education. It has nothing to do with innate intelligence.
For a change, you make "some" sense. But, "Can a teacher's skills change how much a kid learns in a given year? Yes. Is a teacher's skill the most important element in a kid's performance?"........YES!
The teacher if truly interested, can /should make a difference regardless of outside conditions! They have the kids captive for 6 hrs each day. It is those who throw in the towel before they even go to class with 1000 excuses. That is why tenure needs to be eliminated along with teacher Unions who protect bad teachers.
If a teacher truly wants to make a difference, they can.