If you’ve blocked out your middle school days to the point that you only vaguely remember gym class and locking yourself in your bedroom (we understand), allow us to refresh your memory. A well-stocked pencil case was not complete without one of those four-color retractable pens. This novelty writing tool was key for everything — from taking notes in rainbow hues to spicing up your average classroom doodles. Basically, it was a backpack staple.Consider the Clarins 4-Colour All-in-One Pen the graduated version of that school necessity — only it suits your grown-up beauty routine. Instead of barrels full of multicolored ink, you’ll find three smooth, creamy eyeliners in black, rich brown, and royal blue, plus a lipliner in the perfect neutral shade. Makeup-bag minimalists will delight in the tool, but it’s also handy for anyone who wants to keep their essentials in one grab-and-go place. Which is everyone, right?If you’re willing to overlook the more trying times of your adolescence and embrace the waves of nostalgia this limited-edition pen is likely to evoke, then hit up the Clarins website the first week of January to snag your own for $30. There are some things that are best left in the past, but unlike your high school boyfriend, this isn’t one of them.