When one Reddit user posted a photo of a strange, sharp-looking metal object found in their grandma’s kitchen drawer, the internet lit up with curiosity.

“Any idea what this thing is?” the user asked. “We think it’s some sort of old-school can opener, but we really have no clue.”

Cue the digital treasure hunt.

Within hours, thousands of internet sleuths chimed in—some with genuine guesses, others with vivid (and painful) flashbacks.

One user wrote, “Old school can opener… puncture the can and lever it around to slice the lid off. Made great jagged edges. Also: metal shards, bonus feature.”

Another added, “Still have the scar from when mine slipped and jabbed me in the arm. Those things were brutal!”

And one particularly memorable comment simply said: “That thing went right through my hand once. Never again.”

So, what was it?

Turns out, the mystery tool was indeed a vintage can opener—the kind that practically came with a built-in tetanus risk.

The Can-Opener’s Cutthroat Past

Canned food came long before any bright ideas on how to open it. Early cans were practically mini fortresses, requiring brute force—or a bayonet—to crack open.

That changed in 1858, when American inventor Ezra Warner designed the first actual can opener: a lever-style tool with a sharp curved blade that could punch through tin. It worked well enough for the U.S. military during the Civil War, but was a nightmare in civilian kitchens.

In 1870, William Lyman improved things with a rotary cutting wheel—finally making it possible to open a can without a first-aid kit nearby. Still, many homes stuck with the original stab-and-slice models well into the 20th century.