Well I think it's a great decision to go back to school. I'm in my 3rd year of science doing a Bsc at the UA.
Yeah, there is that 'old-guy' in 2 of my classes who asks about 15 questions PER lecture. Yes. We all hate him.
But that said, there are some other old people who don't really say anything, and we treat them as anyone else. I think it's moreso the fact of asking many, many, many questions in class that doesn't pertain to the lecture material at all.
If there is anything I learned, education is definately worth it. Yeah, my first two years were a drag, but now that i'm specialzing in things I really enjoy, I actually wake up early to study!
As they say, your first two years are ALWAYS the hardest. Suck it up and your last two will be fun.
For people who say what's the point? You get to learn things not too many get the chance to do. It changes your perspective on how things operate and your mentality of thinking... something only education can do.
As for good classes to take, my favorites have been Microbiology (lab really blows though), Pharmacology, Neurobiology, Animal/Human physiology. Those pertain most to my life and I think it's 'hella interesting'
Another intersting one I'm taking now is Modern physics. So Einstein's theories of relativity etc. Fascinating, but a little difficult with the concepts.
Classes that I've wanted to shoot myself in:
Cell biology, Biol 108 (not sure what it's called ) has to do with Phylems and all that boring stuff. Elementary physics.
Chemistry. The Labs are insane. 3-4 hours of your life every week wasted, and it's hard as hell.