Here's the question you clicked on:
sasogeek
I have a question which isn't a typical mathematics question, more of a discussion, sort of. but here is, does a mathematics major study everything in mathematics? say, linear algebra, number theory, complex analysis, calculus, etc... or they specify in only a selected number of topics?
At some point you have to specialize, but all the topics you named are surveyed by a typical math major in the course of their education.
...but eventually they specialize in, say, cryptography (I think that is what myininaya is doing) and delve deeper into that particular subject. Statistics is another example of something you can go pretty deep with. Ask Zarkon about that ;)
May want to see if @across has anything to add here :)
And @myininaya of course.