For this kind of little-known yet strangely fascinating knowledge, the internet is a goldmine.

Spending a lot of time online teaches you new things every day, whether it’s the hidden uses for the hooks on shopping carts, the meaning behind the initials of M&Ms, or the proper use of a cheesegrater’s fourth side.

However, a recent discovery regarding restrooms has the internet confused.

One writes, “I’m glad someone asked because I’ve been wondering this for years but never googled it.”

Another adds, “I can’t believe I’ve been living with a WC sign and had no idea why it was called WC.”

“I was 23 y/o when I learned,” somebody else comments.

A fourth says: “I know, but don’t use it (don’t use the word—do use the WC).”

Others, however, are astounded that people have lived their entire lives without understanding what ‘WC’ actually stands for.

A second person questions: “What?! Who doesn’t know this?”

“Surely everyone knows what ‘WC’ stands for?” asks a third.

The real meaning of “WC” actually makes perfect sense when you break it down.

The history of toilets serves as the basis for the name’s derivation.

When homes started to install indoor plumbing, a lot of people converted their clothes closets into little spaces equipped with toilets.

The house only had flowing water in a few of these locations.

These days, a lot of people call the space housing the toilet the bathroom.

But historically, a bathroom was a room with a bathtub that was entirely distinct from the toilet.

In a now-deleted TikTok, @itsnathannyc explains: “Before indoor plumbing, we actually had a room for the bathtub, a bathroom. But the spout was outside. You had to carry water in with a bucket, heat it up, and pour it in the tub.”

“Indoor plumbing comes along, and there is already a room with a bath, the bathroom, so where do you put the toilet? Just put it in a closet; it’s the easiest place to put a toilet.”

They subsequently earned the nickname “water closets” since they were among the few locations in the house with running water.

“To start, WC is an abbreviation standing for ‘water closet’, a name used in the 1900s for a toilet, due to most being fitted in a spare closet or cupboard. Over time, WC has been used instead of bathroom to describe a room with a toilet but no bath,” per Plumb World.

The TikToker then reveals that the acronym WC stands for “water closet.”