We've got 20/20 vision in 2020! We're taking a look back at some of the biggest celebs from when they were just bright-eyed 20-year-olds. Some, like Madonna, weren't famous yet, but you definitely knew Britney Spears and Justin Timberlake well by the time they turned the big 2-0. See what even more A-listers looked like at age 20 by clicking through the gallery.