I have all sorts of conflicted feelings about my time with SA during the Bush years when I was a college student. It was fun, but I think the time I spent there cost me a point or two off my GPA. The people I knew of that went off to the Microsofts, Googles, Apples, and various startups of the world were more focused in their studies and their technical passions and didn't pay too much attention to many of the things…
It's a good habit to periodically reflect: would I be happier spending more time there, or would I be happier spending more time [working on that side project, with my family, watching a movie, hiking, etc]. Most highly effective people 'waste' their time too, just that they're aware of the decisions they make, and strike a good balance. It's important not to let play get in the way of work, but work isn't the only thing worth living for.