Woman discovers the shoulder button on jackets is for holding hand bags in place.

Meet Francesca. She has a halo of hearts around her head, for a very important reason (jk that's a filter).

Francesca recently made a mind-blowing discovery. A discovery that just might change your life forever. It changed mine.

The discovery involves that button on the shoulder of many jackets and coats. Most of my jackets have one, but I always thought it was decorative. Wow, was I ever wrong.

"Taken me 18 years to find out that the weird shoulder buttons on jackets is to hold your bag in place so it doesn’t fall off," she writes. "Who knew."

WE DIDN'T KNOW, FRANCESCA.

As a woman with narrow shoulders (#humblebrag), my bags are constantly falling off—especially when I'm wearing a jacket or coat. So this is major news. And, frankly, I'm irked no one told me. Did you know????????

I'm clearly not the only person who was ignorant on this subject. Twitter is exploding with gratitude for their newfound knowledge.

And it turns out, this function traces back to the military, when it was used as part of soldiers' uniforms:

THE MORE YOU KNOW.

The article originally appeared on our partner site someecards and was written by May Wilkerson.