You know when you have one of those "I was today years old when I realized..." moments? This is one of those moments.

It's pretty much a law here in New Jersey to have watched HBO's The Sopranos. It's widely regarded as one of the greatest TV shows of all time - if not THE greatest.

The Sopranos TV Still
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In fact, it's my favorite show of all time! I've watched the show in its entirety three times now, and this little-known fact has flown under my radar every time!

One of the biggest pop stars in the world was on an episode in Season 3! And I was flabbergasted when I found out who it was.

(By the way, if you still haven't seen The Sopranos and you're planning to one day - SPOILER ALERT below.)

Remember Season 3, Episode 9? "The Telltale Moozadell." It's the episode where AJ and his friends vandalized the school swimming pool. As teenage boys are prone to do - AJ and his buddies wanted to impress some girls, so they threw school property into the pool, leaving behind an incriminating pizza box.

But who were the girls watching and laughing from the bleachers? If you take a closer look, you'll see - one of them was Lady Gaga!

25th Annual Screen Actors Guild Awards - Red Carpet
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Of course, she wasn't known as Lady Gaga back then. Here we see a teenage Stefani Germanotta cheering the boys on with the rest of her bad girl posse.

Credit: HBO
Credit: HBO

Need to jog your memory? Take a look at the clip down below. She was so pretty!

A few years ago she even reflected on her brief 2001 acting gig, critiquing herself on the way she laughed. (We're our own worst critics.)

READ MORE: 7 Weird Pennsylvania Laws You Probably Didn't Know About

Fast forward 23 years later, she's a global music icon and an accomplished award-winning actress. She'll be starring alongside Joaquin Phoenix as Harley Quinn in the upcoming film Joker: Folie à Deux.

Maybe I'm late to the party on this one, but I just had to share how cool this was! Did you know Lady Gaga was in the episode?

Own Legendary TV History- Sopranos Booth From Final Episode For Sale

Holsten's, the diner used for the famous last scene, posted on Facebook on the booth is up for grabs on eBay. You can learn more on eBay here.

Gallery Credit: Dave Wheeler

Uncle June's House From 'The Sopranos' is On Sale in Newark NJ- Take a Look Inside!

This house always had the makings of an historic New Jersey landmark. It's been a while since we've seen this house. Here's how it looks now!

Gallery Credit: Austyn

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