Out of Millions of #10YearChallenge Posts, These Are the Ones You Need to See

If you have picked up your phone at all over the past 48 hours, no doubt you will have been bombarded with the #10YearChallenge. It's a simple idea: You just share a recent picture of yourself alongside a picture from 2009. Many celebrities and influencers have shared these flashbacks on their feeds—we love Aimee Song's look back to her early blogging days and Alexa Chung wearing hot pants, a Breton top and shorts. A number of stars look almost exactly the same, such as Jennifer Lopez, Reese Witherspoon and Jessica Biel, making this social challenge the ultimate humble brag.