Strong understanding of String Theory/M-Theory.

[bmw]

Hello all,
I would love to have a strong understanding of String Theory/M-Theory (I'll call it ST from now on), and I understand that for this, I must understand the mathematics behind it.  I do have two very good books on this theory, but it totally confuses me (it has lots of math equations and technical terms et cetera).  I also have a good book on quantum mechanics with lots of mathematics in it too.  Do I need to understand Quantum Field theory, Quantum Mechanics, the mathematics behind relativity, et cetera to move on to ST?  What math courses must I take (I'm on a university)?  What other theories must I understand mathemacally and technically to understand ST mathematically and technically?  Thanks for the help.

P.S.
I do have a pretty good base understanding of Relativity, Quantum Mechanics, and ST; I just don't know technical terms and the mathe behind it all.