Hilary Duff was catapulted into stardom as the lead of Disney Channel’s Lizzie McGuire when she was just 13, and the franchise quickly expanded far beyond television—spawning movies, merchandise, video games, and a level of fame few teenagers experience. But now she regrets saying yes to too much when her career was at its peak. “When the doors start opening, it’s very easy to think the right answer is always yes,” Duff told graduates of Northea…