So this might be a long shot, but hoping there are a bunch of mathematicians/logicians on Fluther I ask thee:

How much and what kind of math and logic must one master to be able to understand Gödel’s “On Formally Undecidable Propositions of Principia Mathematica and Related Systems”?

I realize that understanding differs from person to person, but ignoring that, it’s obvious that one cannot understand Gödel without the necessary knowledge of mathematics and logic.
Also, I’ve already read non-technical works explaining his theorems, but now I’m actually talking about his paper from 1931, and what is necessary to understand it.

Curious because this is at the moment sort of my goal to understand it.