If you just mean you took math courses as an undergraduate, then you should not at all feel like an idiot for not understanding what goes on at MO. The site is for "research-level math questions", as their FAQ says. My guess is that even, say, most PhD students tend to understand only the questions in areas of math they are familiar with.
Yeah. Don't feel bad. I have a graduate degree in pure math, and my comprehension level is only about 30%.
Math is an extremely fractured field at a high level. And so much of it requires getting your head around new and difficult concepts, you can't translate between subfields well.
Someone who speaks fluent Java stands a decent chance of decoding reasonably compex C++ or Ruby or whatever. I mean, some languages are way, way out there, but once you've been around the block a couple times, it's all just code.
Not so in math. A professional geometer talking to someone who does PDEs or complex analysis or topology . . . they have nothing in common. And it would take any of them years of study to close the gap.
