It is only surprising if you think mathematics is more or less equivalent to arithmetic.

I was “bad at math” all the way through school and it wasn’t until I realised how wrong this is that it finally clicked. I still cannot calculate shit unless I have pen and paper but I usually have access to this when solving integrals. I went into a math heavy program at uni without any issue.

I remember reading a while ago that it is actually a problem in education that the only ones who pursue math degrees ate those who could easily grasp the arithmetic heavy parts of math, resulting in a narrow presentation of what math really is throughout school.