“I’m bad at math” is a theory from fourth grade. Run the experiment again with better teachers and more sleep.

A conclusion drawn at nine years old can run your choices for decades. It was formed from a small sample, under whatever conditions existed at the time, and it was never treated as provisional because nobody described it that way. Since then you have avoided the subject, which conveniently prevents any evidence to the contrary.

Treat the old verdict as a claim rather than a fact. Run a small honest test now, with decent teaching and a rested head. The result might confirm it, and at least it will be a result about the person you are rather than the one you were.