Formula (Bag) for Success

I take Tim to the Metro every morning at 5:45 am. We figure that we can save some money on gas and wear and tear on our Suburban if he takes the train to work in the morning. One afternoon I noticed the bag he stuffed all of his important "teacher" papers into as well as a massive chemistry textbook, his sweater, and his lunch. It was a fairly large black vinyl bag with beige trim on the top. Up near the top zipper was a small tag that read "Enfamil LIPIL." Hmm....I pondered. Tim is a veteran teacher who has teaching credentials in life and physical sciences. The range of topics he's taught includes, but is not limited to: biology, chemistry, geology, algebra, physics, geometry, health education, and driver's education (I know - that last one's hard to believe but true). He's usually at school earlier than most teachers and leaves later than the rest. He works year round and teaches before the bell rings to signal that class has...