I wish I'd known how important it is to pay attention in class. I'm a writer. That's what I do - write. So lots of times, I am working on a novel or a fanfiction or a short story in class instead of taking notes. Or I'm reading random articles about LOST or Harry Potter instead of paying attention. Main point is: I'm not paying attention. It happens in a lot of my classes (or it did) but one example stands out the most.
Last semester, I took Microeconomics. Not the highlight of my school career, lemme tell you what. It was boring, dull and I didn't really give a rip about firms and markets. So I'd zone out, check Facebook, update my blog or work on my latest novel. I would tune in every now and then and get down the major points but I wasn't hearing what my Professor was saying. When it came time for the test, it showed. No amount of studying could help me because I had no idea what the concepts meant. I could memorize the terms and spit 'em back out at you but I didn't know what they were. So the first test was a major bust.
And yet I still didn't learn my lesson. I continued to goof off and not pay attention and bombed the second test as well. Then, finally, I learned my lesson and started paying attention in class. On the final test, I actually did well.
So now I'm trying to do better. Trying to pay attention in class, not doing the Internet during class...I still slip up sometimes (especially when said class is particularly boring) but I'm doing a lot better.
I only wish I'd known this sooner...