Miley Cyrus' recent transformation has been one of the most drastic in pop-star history. The singer essentially went from bonkers to bluegrass: She swapped the twerking and inflatable penises for messy hair, cut-up denim shorts, and T-shirts. Her new single, "Malibu," is remarkably more relaxed and clear than her last two records. And there's a reason for that: She stopped smoking weed. Cyrus revealed to Billboard magazine in May that she's currently not drinking or doing any drugs—a surprising revelation given the fact that weed was an integral component of her Bangerz and Dead Petz eras. She told Billboard that dropping weed was "easy" and that she did it so this stage of her life could be "super clear and sharp." And she reiterated this Wednesday night (June 14) on The Tonight Show Starring Jimmy Fallon. “I’m actually the most passionate about what I’m doing with this record than I’ve been—I say this every time, but I loved making this rec...