Not once you become an actual scholar of Mathematics. Then it's very much a tree of fields in terms of "what begot what", and at the level of theorems, not even

Not once you become an actual scholar of Mathematics. Then it's very much a tree of fields in terms of "what begot what", and at the level of theorems, not even a tree but a graph with a huge number of interconnections in which "one thing coming before the other" doesn't even make sense to talk about.