How do I get a career in Mathematical theory? As a kid I used to be really gifted at math and actually kinda liked it but years of changing schools and shitty education never helped

What would I need to study? How would I take classes at an accelerated rate? What special programs could I possibly enroll in?

What do you mean by " mathematical theory"? That's massively, massively broad.

What I mean is developing existing ideas by researching new ideas

For example, if I were to excel in physics as well, and I wanted to substantiate a proof for string theory... I'd need a grant from a university or to be employed by a scientific institution eventually to do this. But how would I get there? I'd need a degree of some sort but I imagine the pacing of standard classes would lose my interest

Like I get the general idea I just have no idea of how I'd go about doing it, since I presume most mathematical degrees are used for applying known concepts rather than searching for something more, and such a thing as I'd desire would only come about in special situations

If you need more elaboration ask again about what specifically I can do so with, but I'm keeping it broad since I don't have any specific idea in mind since the skillset I'd require I don't yet have and that's why I want to know to go about getting it too