[raverbashing]

Yeah, there are a lot of possible divisions and specializations in Math it's not even funny. Most of them unintelligible to "mere mortals".

Also hard to find a job, especially one that uses your work, unless you work in number theory, in this case you have a job at the NSA.

[adrianN]

Number theory is an extremely broad field in itself. I'm pretty sure most of it is completely irrelevant to the NSA. If you do a PhD in any theoretical field you'll almost never find a job outside of academia that uses any of your work.