Oh, how time flies.

It feels like only yesterday we were lusting over a baby faced Zac Efron on Highschool Musical, and wishing we had the wardrobe of Nicole Richie on The Simple Life.

Fast forward to 2017 and our fave celebs have come a LONNGGG way.

From Jonah Hill's shocking weightloss transformation, to Calvin Harris's Neville Longbottom re-birth, Miley's entrance to adulthood and Adele's v. demure makeover, these are the biggest style transformations of all time.

Ah, we've come so far!

PICS: See Jonah Hill's Fit Transformation Over The Years...