Happy Birthday, br Lin-Manuel Miranda!.br Lin-Manuel Miranda br turns 42 years old today.br Here are five br fun facts about br the playwright.br 1. Miranda began writing br his debut musical, br 'In the Heights,' while br he was still in college.br 2. 'Les Misérables' was br the first musical he saw.br 3. He wrote music for br local politicians' ads.br 4. Miranda was inspired tobr write his first musical after seeing br Jonathan Larson's 'Rent.'.br 5. He keeps a math trophy from high school next to one of his Grammys because he's "just as proud.".