This childhood accessory is suddenly cool for grown men, and business guys everywhere need to get one

A guy needs a bag every day - it's as simple as that.

Whether he's going for a quick Sunday trip out on the town, or to work every day, he needs a bag to carry all his modern essentials.

Today, the perfect bag for that is the humble backpack. Relaxing dress codes and a hefty increase in stylish options have caused a serious uptick in guys choosing backpacks over the much stuffier briefcase.

Another benefit - it fits over both shoulders, allowing you to even out the weight distribution and less pain on your shoulders. Many are even padded in the straps - imagine that!

This allows your bag to be much more versatile, and can even be used on the weekends, as it can be dressed up or down. They've completely dumped their schoolboy vibe, and will no longer make you look like you're going to night school.

Even Perry Ellis creative director Michael Maccari told Business Insider that the backpack was the most important men's accessory.

So what are you waiting for? Here are some of our favorites:

Pictured, from left to right: Shinola Runwell Leather Backpack ($950), Want Les Essentials Kastrup Backpack ($495), Filson Journeyman Backpack ($320), Herschel Heritage Backpack ($55).