Anymore math to invent?

[curved_time]

Hi everyone, I'm currently a high school student and I want to be a mathematician when I grow up. I want to be a mathematician that discovers and makes new math, like the ancients such as Aristotle. Problem is, I don’t know if there’s any more math left to find. Literally every time I find something new in math, I find out that it has already been discovered and it's sad. Open to any of your opinions.