“I’m not a math person” has failed more tests than math ever has.

Describing yourself as a certain type of person turns a temporary gap into a permanent trait, and once that is settled, effort looks pointless, so you stop, and the gap grows into evidence for the original claim. The sentence does its own work. Most people who say it hit one bad year with one topic and never went back.

Swap the wording and see what changes. I have not learned this yet, or I got lost around fractions and never caught up. Both of those point at a specific thing you could actually fix, which is a much better place to stand than a label.