Ten years ago, life looked very different. In early 2009, Barack Obama was inaugurated into office, the concept of an "Instagram influencer" simply did not exist, iPhones were just about brand-new, and none of the Kardashians had kids yet.

Back then, times were ostensibly simpler, but as those times have certainly changed, so have the faces of most of your favorite celebrities. This week, the Instagram meme to watch out for is the nostalgic "10-Year Challenge," which involves seemingly ageless celebrities like Reese Witherspoon comparing photographs of themselves from now with those from 10 years prior. It's only the latest in a string of narcissistic trends to take social media by storm in recent weeks, following that ubiquitous face-matching meme that involved using the website to find out what percentage of your face matched with your various celebrity doppelgängers.

No one can resist picking up those old photo albums (or rummaging through that camera roll) and exposing what they may find. The responses from celebrities participating in the 10-Year Challenge so far have ranged from cheeky to serious: Sarah Silverman posted the same old photo twice, as did The Good Place's Jameela Jamil in an effort to continue her anti-fad diet crusade, while 13 Reasons Why's Tommy Dorfman used the meme as an opportunity to open up about his addiction in his teenage years. Since 2019 has only just begun, some celebrities like Kate Hudson are using photos between the years 2008 and 2018 for their own entries in the challenge, and others, like Padma Lakshmi, are showing you how they've changed in not just one decade but two. Even Cynthia Nixon took a stab at the meme, indicating that she went "from Cosmos to Cuomo" in just 10 years.

Time and gravity eventually make fools of us all, but whether your favorite celebrity actually looks any different from how they used to look 10 years ago, there's one thing all of these memes have in common: They demonstrate personal growth.

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