Before he cut off his hair and became Robin Thicke, "Blurred Lines" singer, Robin had hair to his shoulders and looked like Constantine from American Idol.
When she was Hannah Montana, Miley rocked long, brown hair like the rest of the Disney stars. But now that she's a rocker chick, her super short blonde 'do suits her perfectly.
Mel C. was known for her high pony during the Spice Girls heyday, but she also rocked a short blonde bob with blunt bangs circa 2000 when she was pursuing a solo career. My, how times have changed.
Now Mark Wahlberg is one of Hollywood's finest, but back in the days of Marky Mark, he rocked baseball caps and boy band hair. Oh, the memories.
Christina Aguilera's new look is amazing—we're talking about both her 30 lb weight loss and her overall glow—but let's not forget that during her Xtina days in the early 2000s, The Voice judge's hair had black and pink streaks. Yup.
Everyone has their own opinions of Justin Timberlake's new, slicked back do, but we can all agree that it's a major improvement from his curly, Ramen noodle hair days, yes?
Britney Spears looks amazing lately and her hair now is certainly an improvement from her bald-headed look circa 2008. But back in the late 90's, Britney's dirty blonde locks made her look so young and (not that) innocent.
Jessica Simpson has had more hairstyles than she has pants sizes, but we think we love her long, wavy half blonde half brown 'do the best. We bet Nick Lachey would agree.
And speaking of Simpson sisters, remember when Ashlee had black hair, side bangs, and looked like a punk rocker? Now she's got a blonde bob (and a nose job) and looks amazing.
Take a minute to think about how hot Nick Carter is lately. It's true! But let's not forget that when the Backstreet Boys were just starting out, Nick had highlights and spiked his hair with an abundance of hair gel. Ha.
Rihanna rocks a different hairstyle on the daily, but back when she only had one single and zero Grammys, Rihanna had long dark extensions and slick-straight hair. You like?
Lil Bow Wow
Bow Wow has grown into a legitimately good-looking guy. Now he rocks a super short 'do, but we can't forget those corn rows. Never forget the corn rows.
We can barely see the Bieber hair anymore since he wears ridiculous hats to cover it up, but what made a 15-year-old Biebs famous in 2009 ish was his shaggy locks and hair flip. Ah, the good ol' days.
Beyonce is the Queen of many things, changing up her hairstyles being one of them. We'll miss the Farrah Fawcett style she rocked during the prime of Destiny's Child.