It is a well-known fact that drinking water is very important for optimal brain function; so if student hasn't brought water to the tutoring session, I will often send him/her out for a water break half way through the session. This also enhances learning by shortening the first study session, because the longer the study session, the more information that is forgotten. Why? People remember the most from the beginning and the end of a learning session--in the classroom or on their own. The "middle" information is the hardest to remember; so the shorter the session, the less "in-the-middle" information there is to be forgotten. The student comes back into the tutoring session with a re-charged brain, ready to learn again.