I have a kind of similar story. In 7th grade math, I never did my homework, but I found most of the stuff I was learning to be really easy.

I got a 94 on the first large cumulative test of the year. As the tests were being handed back, everyone noticed my grade and started making a big deal out of it. The teacher said in front of the entire class, "Those two numbers should have been flipped around" (i.e. I should have received a 49). In hindsight, I think that was a violation of FERPA, but that was also 22 years ago.

I hated that teacher, honestly really killed my interest in math throughout grade school (I never even did trig in high school). I ended up studying physics in my late 20's and really excelling at the math part, but looking down the barrel of grad school, I thought better of it and dropped out. For those interested, the most advanced math classes I took were basic upper level physics-related math. PDEs, Linear Algebra, and Vector Analysis.

I often wonder what might have happened if that teacher gave me a vote of confidence and tried challenging me instead of shaming me publicly. Oh well, I'm an artist now.