Nothing promotes a nap like a difficult book.  Studying.  Trying to understand something difficult. Study circles, obliging and mentally superior friends, discussions and debates, and yes, a nice beverage or snack: these are useful solutions and the library cafe is a powerful way to make them more productive.  Informal, resource-rich and caffeinated or not, it sometimes beats sitting at home alone to get that homework done.  For those of you scandalized by the thought of coffee stained resources, consider that heavily used and margin annotated and graffiti marred books have more to offer than the pristine volume nobody reads.  Have you never appreciated the notes in your used textbooks, and learned a lot from them?