A Stock Phrase.
When referring to a specific group, refer to You Know What They Say About X...
When the character refers to himself saying something, regardless of whether or not he actually does in the series, the trope is It's Like I Always Say.
- The Boondock Saints
Doc: You know what they say: People in glass houses sink sh-sh-ships.
Jack Payne: You know what they say is the first thing that a man feels when he shoots a civilian?
- The Devil Wears Prada
Nigel: You know what they say. Tiny man. Huge ego.
- In Cannibal! The Musical, there was a scene where the town's drunken sheriff informs Packer that he's going to be hung at sunrise, then adds "You know what they say about sunrise?", awkwardly pauses for a moment, and just wanders off. According to the commentary, the actor (who actually was drunk) had just forgotten his line and walked off camera - Trey Parker opted to leave it in because he decided that it was funnier than the actual punchline.
- In The Room :
Johnny: You know what they say: love is blind.
- Anyway, how is your sex life ?
- In Airplane! :
First Jive Dude: Hey, you know what they say: see a broad to get dat booty yak 'em...First Jive Dude, Second Jive Dude: ...leg 'er down a smack 'em yak 'em!
- The Office
- "Traveling Salesmen"
Michael Scott: You know what they say. Fool me once? Strike one. Fool me twice? Strike three.
- "Traveling Salesmen"
- Two and a Half Men episode "Shoes, Hats, Pickle Jar Lids"
Courtney: You know what they say: when you assume... you're just a bitch.
- NCIS has two variations on the You Can't Make an Omelette... saying:
Leroy Jethro Gibbs: Well you know what they say, Jen. Can't make an omelette unless you break a few eggs.—"Under Covers"Officer Ziva David: Well, you know what they say. You cannot make an omelette without breaking a few legs.—"Knockout"
- Smallville episode "Leech":
Jonathan Kent: You know what they say: Lightning never strikes twice in the same place.
Chandler: You know what they say, ask your slippers a question...you're going crazy.
- Buffy the Vampire Slayer episode "Blood Ties"
Willow Rosenberg: Well, you know what they say: The bigger they are...
Anya: The faster they stomp you into nothing.
- Gilmore Girls episode "Lost and Found":
Lorelai: You know what they say.
Luke: No, what do they say?
Lorelai: Never ever date a guy who owns a single bed...it means he's not open to a commitment.
- The Golden Girls: "You know what they say: you can lead a herring to water, but you have to walk really fast or he'll die."
- That '70s Show episode "Bye Bye Basement"
Leo: You know what they say, Rome was built in a day.
- The Wire episode "Game Day"
Det. James 'Jimmy' McNulty: Well, you know what they say: "Stupid criminals make stupid cops."
- CSI: NY really likes this one.
- "Zoo York"
Dr. Evan Zao: You know what they say: It's a dirty job but...
Det. Lindsay Monroe: The rookie's gotta do it.
- "The Box"
Reggie Dunham: You know what they say, right? Mind's a terrible thing to waste.Det. Mac Taylor: So's my time.
- "The Party's Over"
Det. Mac Taylor: You know what they say: keep your friends close and your enemies closer - and if that doesn't work, kill 'em.
Det. Jo Danville: [about a gun created with a 3-D printer] You know what they say: every act of creation is an act of destruction.ME Sid Hammerback: [on giving away his fortune] Well, you know they always say you can't take it with you.
- "Zoo York"
- CSI: Miami
Horatio Caine: You know what they say. You lie down with the Devil, you wake up in Hell.
Caine: You know what they say, Frank (puts on sunglasses)...speed kills.
- On another episode:
- Hannah Montana episode "Miley, Get Your Gum"
Robbie Stewart: You know what they say, every now and then even a blind pig snorts up a truffle.
- The Sopranos episode "Cold Cuts"
Anthony 'Tony' Soprano Sr.: You know what they say: Revenge is like serving cold cuts.
Darla: Well, you know what they say... life's full of surprises.
- Burn Notice: "Yeah well, you know what they say about holding a snake by the tail, Mike."
- Prison Break: "You know what they say about weather in the midwest: if you don't like it, wait an hour."
- Played with on Sports Night:
Dan: You know what they say.Casey: About what?Dan: About money won.Casey: What do they say?Dan: I don't know. I'm asking.Casey: They say it's twice as sweet as money earned.Dan: How come you said 'what do they say'?Casey: It was an alley-oop pass. I was dishing you the ball.Dan: You were. And I completely missed it.Casey: I was there for the putback.Dan: I wouldn't have been able to do anything with it anyway.Casey: That's right.Dan: Because I didn't know the expression.
- Lady Gaga's video for "Telephone": "You know what they say: Once you kill a cow, you gotta make a burger."
- Mika's "Lollipop"
"I was walkin' with my mama one day
When she warned me what people say:
Live your life until love is found
Cause love's gonna get you down."
- Rebecca Lynn Howard's "Forgive": "You know what they say / Forgive and forget, re-live and regret."
- In Spamalot, Patsy says this line to a depressed King Arthur. Arthur apparently does not know what they say.
- Hotel Mario does this in the second hotel when Mario stumbles upon a room full of toasters that have been causing blackouts in the entire hotel, to which he comments, "You know what they say... All toasters toast toast!" before unplugging them.
- Shadow the Hedgehog has the Egg Breaker boss fight (Eggman in a Mini-Mecha). The version of this boss fought in the Mad Matrix level is a Flunky Boss who says "You know what they say! The more, the merrier!" when he uses his Enemy Summoner attack. Every time he uses it. And he often uses it many times in succession.
- Just Cause 3 gives us this from Rico: "You know what they say about a guy with a big statue...
- Parodied in an episode of Ed, Edd n Eddy: Edd and Eddy are discussing some problem, and Ed, who was not involved in the conversation, chimes in with "You know what they say," and then immediately goes back to poking around in his locker, ignoring the other two. An awkward pause ensues for a few seconds while they wait for him to finish.
Ed: You know what they say, Double D. (he shoves Eddy's mouth to an opened pipe on the side.) "If you're thirsty, take a drink."
- In "Mirror, Mirror, on the Ed," Ed pretending to be Eddy gives us:
- The Simpsons
Homer: You know what they say sometimes you have to break the rules to free your heart.
- Phineas and Ferb
Roger Doofensmirtz: You know what they say, "You can't be T'd off once you've T'd off'." Heheh...that was very funny...Heinz Doofensmirtz: What?? Who says that?Roger Doofensmirtz: You know, They. Those guys over there. (points to a pair of Creepy Twins saying "You can't be T'd off once you've T'd off.") Creepy, right? I've been trying to ditch those guys all day!
Heinz: You know what they say about taking the easy way.Vannesa: What do they say?Heinz: I could tell you, but that would be taking the easy way and you know what they say about that.
- Bonus? Their names are actually They.
- Doofenshmirtz did it once.
- My Little Pony: Friendship Is Magic: In "Fake It 'Til You Make It", Rarity suggests a new outfit might give Fluttershy the confidence to run Rarity's Manehatten boutique while Rarity herself is at a big fashion show in Canterlot.
Rarity: You know what they say, "clothes make the pony!"
Fluttershy: Um, who says that?
Rarity: You know, "them".