Ross' food allergies are revealed in season two after he has an allergic reaction to Monica's kiwi-lime pie.

During the trivia game to see who gets the apartment in Season 4, Monica's fear of clown dogs is revealed, although the girls eventually lose when they can't identify Chandler Bing's job.

Ross brings his girlfriend Bonnie on a beach trip in Season 3, only to have Rachel shave her head.

In Season 8, Chandler finally gets Monica to reveal the contents of that mysterious closet, which is filled with a very un-Monica-like mess.

In Season 2's "The One with Phoebe's Dad," Phoebe asks a framed photo of Albert Einstein, whom she thinks is her grandfather, to wish her luck.

In Season 2's "The One Where Joey Moved Out," Phoebe and Rachel decide to get tattoos, but Phoebe chickens out and Rachel ends up with a heart tattoo on her hip.

In Season 3, Joey puts on all of Chandler's clothes (except for underwear) and does lunges.

It was the only song that worked!

The Magna Doodle had a different saying or picture each episode.

Joey buys the chick from an animal sanctuary as a gift for Chandler, but when Chandler goes back to return it, he sees that the chick might be euthanized, then brings back the chick AND a duck.

In "The One with George Stephanopoulous," the girls get his pizza and then spy on him from Monica's balcony.

As she revealed during Season 5's "The One with All the Thanksgivings," Monica dropped a knife through Chandler's wicker shoes, severing his pinkie toe. She brought a carrot to the hospital instead of his toe. As you might remember, though, her way of apologizing was epic.

David (Hank Azaria) first appears in Season 1 as a love interest for Phoebe, but they break up after his science career summons him to Minsk. He returns in Season 7 to try to woo her again.

Yep. (Chandler played the background dancer on the left growing up.)

Emily was the niece of Rachel's boss, whom Ross meets when Rachel pawns off the pair's opera date on him.

The song "I'll Be There For You," later famously recorded by The Rembrandts, was originally also offered to R.E.M.

Joey accidentally bids on a boat at a charity auction in Season 6's "The One with the Proposal," but after he and Phoebe try to convince the next highest bidder, Mr. Beaumont, to take it so he doesn't get saddled with the price, he decides to keep it and goes with Rachel's suggested name, the Mr. Beaumont.

After Monica and Chandler have packed up for the suburbs in Season 10's finale, Monica notes that they've got some time before the big move. Rachel asks, "OK, should we get some coffee?" Chandler replies, "Sure! Where?"