The 70s, 80s, and 90s gave us so much good stuff. (We love you, Fleetwood Mac and smartphone-free family dinners.)But when it comes to beauty? Let's just say there isn't quite as much to feel nostalgic about. Even though each decade was defined by very different styles, they all had one thing in common: makeup that seems kinda crazy today. (Not only did makeup trends baffle us, but how about these old-school dating rules that we can't believe existed?