If you wear a shirt every day, chances are you've never wondered why men and women’s shirts button up on different sides every time you reach for your daily outfit.

Maybe you’ve never even thought about it, but if you’re wearing a shirt made for women, the buttons are fastened from right to left, and if you’re wearing men’s clothing, they button up from left to right.

There isn’t a straight-forward, obvious answer for this one, as it's one of those things that “just is”. It’s been a part of men and women’s tailoring for centuries, and has gone down in the fashion history books.

It would make sense if all women were left-handed, and all men right-handed, right? But we know that simply isn’t true.

So what’s the deal?

One theory, of course, dates back to men on the battlefield. Most men being right-handed, it made for easier access into jackets and coats to retrieve weapons and the like, and this translated to shirts, too.

Then why, pray tell, are women’s shirts different?

Another theory is that back in the day, women weren’t able to dress themselves (poor souls), so their servants would fasten up their clothing for them, facing the buttons, and thus the right-handed buttoning for the wearer, became the right-handed buttoning for the dresser (left-handed for the wearer).

Another theory unfortunately dates back to the outdated notion that women are inferior to men.

In 1894’s Man and Woman: A Study of Secondary and Tertiary Sexual Characters, Havelock Ellis writes that women are inferior to men in “strength and in rapidity and precision of movement,” which dictates which side they button up their shirts (apparently).

Of course, there's no real reason why fashion brands continue to create shirts with buttons on opposite sides these days. It's something they’ve always done, and continue to do.

Chances are you may not even notice, but it's a fun sartorial quirk from the past that we continue to live with on a daily basis.