It's hard to believe that Justin Bieber is a married man [1] now — it seems like just yesterday that he was an up-and-coming child pop star with an iconic haircut and a legion of young fans. Though his career began in 2007 [2] at the tender age of 12, he's is now more than twice that age. He's transformed over the years from the "Baby" singer to a total babe of a singer [3], and if you're wondering when exactly that happened, you're not the only one. Let's take a walk down memory lane to see Justin's transition from boy to man over the past 13 years.