Let's say I get some serious head trauma and I forget all about mathematics, starting again at basic arithmetic. No real limits here.

What 'path' of education through subsequent math courses would you take me through so I could actually understand it all, and where would you finish and end the studies so that I could benefit society in some way?

I'd refresh everything and master some of that good ol' topology if I could. I feel like my previous investments into fields not heavily reliant on geometry has clouded me.