Forgotten celebrities are a brutal reminder of the fleeting nature of fame.

In an industry where you're hot one minute and totally irrelevant the next, it's no surprise that there are once-famous actors and singers you probably don't remember. From teen heartthrob Jonathan Taylor Thomas to Gossip Girl's Taylor Momsen and Jesse McCartney, plenty of stars basically disappeared from the limelight without a trace.

Below, discover celebrities you completely forgot existed.

Celebrities We Totally Forgot Existed