It is reported that Albert Einstein had difficulty learning Calculus. The
man
was a Physics genius but needed help with advanced math.

it was differential geometry that Einstein was unfamiliar with. when
formulating relativity, he realized that he needed tools that he was not
familiar with. so he went to a mathematician friend and learned which tools
he needed.

please understand this in the context of 1912. differential geometry was
fairly new back then, i believe it came from Riemann.

it's possible for some branches of math and physics to be relatively arcane.
for instance, de Borges attempted proofs use operator theory. most
mathematics students cannot read his papers. in fact, most professional
mathematicians can't read them either. the only reason that de Borges proof
of Bieberbach became accepted is that it was rewritten by other Europeans.

it's not uncommon for a theoretical physicist to have to learn a new branch
of math to solve a problem. for instance, string theorists working on the
landscape turned to statistics.

Gravity