Mary is a good student, and a tad independent. At 18, she’s getting ready to graduate from a Catholic high school with honors. And every once in a while, Mary smokes pot with her friends—friends she’s had since grade school. Leaving a concert at US Bank Pavilion, Mary and her friends stop at Denny’s. In Mary’s purse is a dime bag of pot. It’s been there for weeks, and she hasn’t really thought it.