Someone is reading my user page? Certainly you have better things to do!
I've always enjoyed learning, even if (well, especially if) what I'm learning isn't required of me by a teacher or professor. So naturally, Wikipedia is one of my favorite sites, and a culprit for many late bedtimes. I can't call myself an expert on anything, but give me some time to get through college/grad school, and let's see what I can contribute. In the meantime, I'll just chip in where I see fit. Correcting grammatical errors or typos is one way I often contribute, but chances are I've made my own mistakes.
I'm the happy parent of a handful of Wikipedia articles. Of course, these articles will only succeed if the rest of Wikipediadom adds their own knowledge and input.