Study Physics. I'd take the math prerequisites and not understand what this is useful for, and then the first week of physics class we'd review the math and suddenly it would become quite practical.

Solid advise. I think finance massively recruits maths aptitude from physics for precisely this ability to connect hard core maths to models of the world.

I wouldn’t expect a pure mathematician to be good at this nor to care about it either.

Did you ever read “How to Solve it?” Polya says he became a mathematician because he was too clever to be a philosopher and not clever enough to be a physicist :)

Not all math has applications; some of it is just interesting for its own sake.