McKayla Maroney
doesn't smile much now…but she did back in the day!

The Olympic gymnast tweeted the adorable childhood pic with the caption, "Happy Friday" ... and she does look pretty excited in the cute candid.

Maroney generated a ton of media attention for her "Not Impressed" face at the 2012 Summer Olympic Games when she won the silver medal.

The brunette beauty has definitely capitalized on the whole not-smiling-shtick ... she even got President Obama to make the infamous face with her in a photo op last November at the White House!

McKayla's definitely still the spitting image of her younger self -- and she's got one great smile (we wish she'd show it off more!).

Click "Launch Gallery" above to see more stars before fame including another Olympian, a strikingly different looking Maria Menounos, some of the "Jersey Shore" kids and more! 

Hot Videos