In "Free Cake", Rigby says something along the lines of "Did you go to medical school in the last five minutes?" exactly five minutes into the episode.
Also, during the commercial for Fist Pump in Caffeinated Concert Tickets, the announcer mentions that Fist Pump's demographic is people within the age range of eleven to fifteen. However, the end of the episode shows the concert to be completely full of adults, with absolutely no adolescents in sight. Regular Show itself has a similar scenario - it's on Cartoon Network, which is primarily a kids' network. However, the more mature level of humor and content (like Fist Pump's declaration of having been just been released from jail and rehab) causes it to primarily be viewed by an older audience. It's all a Lampshade Hanging on Regular Show's own demographics!
Also, eleven to fifteen year olds is the show's own demographic, which adds to the brilliance.
You can also think of it this way - during the entire episode, the characters comment on how this is a band that "was cool back when they were younger". The entire crowd at the concert are probably all the old fans, since they're outdated and aren't attracting any new ones.
Doubles as Fridge Logic when you remember how Cartoon Network had came under fire before in the last decade for their hypocritical practices of using Live Action and a fair share of unpopular new shows killing off the classics; in summary, it was their existence being, quoting Peter Griffin, "a little hipper to bring back those boys you scared away."
May not be Fridge Brilliance, or intentional, but most people are always pitting Regular Show and Adventure Time against each other. Well, if you know AT, you know Finn, Ice King, and possibly Susan Strong are pretty much the only humans. But in Regular Show, all the main characters are either non-human or some weird human. However, almost all the other character extras are humans with no notable differences. It could be a coincidence, or it could be the animators intending Regular Show and Adventure Time to face with each other.
For Pops' horror story in the Halloween episode, it was pretty flimsy and flat for a "scary story". Then I realized that Pops probably gets scared by horror movies pretty easily and only catches them in glimpses. And when the evil doll said "Mark on your face", it could have been easily "Carve your face" so Pops wouldn't be scared of his own story.
Proven in the second Halloween special, with Pops being scared at even the smallest scary story detail.
In "Do Me A Solid", Mordecai and Rigby get into a sort of war based on favors. Eventually, under the threat of the world ending, Mordecai is forced to do one last embarrassing task of Rigby's in front of everyone. This task involves squatting down and making sounds similar to an airplane backing out of a runway. It's pretty obvious what that signifies. The brilliance? MORDECAI WAS DOING RIGBY A SOLID.
Using The Beach Boys' "I Get Around" in "Skips Vs. Technology". Considering that most of the music the show licenses is from the 80's, The Beach Boys (who were most active in the 60's) could be considered outdated for this show, just as Skips considered himself outdated in the episode.
In "Video Game Wizard", Skips is shown to be really good at video games despite him rarely playing it. Why is that despite him having trouble using a computer? Because in "Fist of Justice", the controls of to the "Fist of Justice" are similar to a game controller and he has to use them every 157 years to fight The Guardians of Eternal Youth's evil brother, Klordbane.
My Mom shows Muscle Man, who Mordecai considers just a Fat Idiot, supervising Mordecai and Rigby. He does an excellent job of that: shows them how they can slack at the job as long as they have won Benson's trust and really accomplish the missions he assigns. Also that Benson, as the boss, deserves to be informed about what his employees are they doing every time. Muscle Man even broke traffic laws because he knows the cop is his friend. He asked the guy at the greenhouse to carry the tree (because it's his job and he knows how to do it right) and even treats Mordecai for the videogames. The thing that makes Muscle Man borders Magnificent Bastard is that his "joke" is a Batman Gambit: If Mordecai would not have used his Condescending Compassion with the "My Mom" jokes, he and Rigby really would have enjoyed Muscle Man's "supervision". So, if like Muscle Man, you can be a Slacker immature guy but if you could not get respect from your coworkers, at least you could get revenge.
Muscle Man's plan to get revenge on Rigby and Mordecai in My Mom and See you there both involve a Batman Gambit: If Rigby and Mordecai would not treated Muscle Man with Pity Perversion or accepted Muscle Man�s decision to not invite them to HFG' party, they would not get humiliated so badly and Muscle Man would have get a great time anyway. He spent considerable resources, but he would have won in any scenario a true Magnificent Bastard?
For part of Dead at Eight, Rigby carries Muscle Man around his neck, in the form of Death's soul-containing amulet. In Muscle Mentor, Muscle Man returns the favor by carrying Rigby in the "Mentoring Harness."
In "Cruisin'," Mordecai and Rigby sport cheesy smiles to feign confidence. When Rigby points out that "no human ever makes this face," two women immediately get in their car. Of course, the faces worked because Rigby and Mordecai are not human.
In Fancy Restaurant, Starla's parents always seem to follow Muscle Man's cue. This would seem table manners at first, since Muscle Man is the host, but it also makes a lot more sense after the reveal that they are not fancy either and just imitating Muscle Man, whom they believe is fancy.
In The Best VHS in the World, we find out Rigby has a bra that he likes to refer to as his butt-cheek pants. This may seem like his usual immature humor, but when you think about it, he may be wearing them due to him being the one-cheek wonder. This is also quite similar to the way women will wear a bra made to make it seem like they have larger breasts.
In 'Exit 9B', Death joins in on the Park's side to combat the army of resurrected villains. All the villains just escaped from Hell, Death was probably doing his job and helping return them to the afterlife where they belonged.
In "Dead at Eight", Death and his wife were pretty mad at Mordecai and Rigby for wrecking their home while they were babysitting their son, Thomas, but they got over it when they see that they got him to go to sleep, despite a glass chandelier being on top of him. So why aren't they that mad at Mordecai and Rigby despite the situation they were in? Because this probably wasn't the first time that this happened when someone babysits Thomas. Death was impressed that Mordecai and Rigby didn't die considering that the previous babysitters all died, thanks to Thomas, and tells them they did a better job than them. So at this point, Death and his wife would be happy to have a babysitter to get the job done.
Death's wife also asks Mordecai and Rigby if they have experiences taking care of "paranormal children", so one should expect these kind of children to cause more trouble than regular ones as Thomas demonstrates.
Rigby having only one butt cheek and being called "The One Cheeked Wonder" is funny enough, but the joke doubles when you realize that he does his work as "Half-Assed" as possible.
In "Carter and Briggs" Rigby says his favorite thing about an action-y, inane, cop show is the realism. Considering the bizarre universe Regular Show takes place in, two cops shouting things about donuts and getting angrish while shooting at helicopters is probably considered realistic.
Also, Carter and Briggs love doing donuts. Think about it. They're cops. And they love donuts.
Same with Muscle Man, he likes doing donuts too, and he likes to eat fatty foods.
Eileen is the only recurring character to wear glasses. She's also officially a mole, "which are known for having terrible eyesight."
In "Mordecai and the Rigbys," Mordecai is singing to impress Margaret- "which is what male birds do to attract females."
In "Cold Cubed", Thomas didn't get brain freeze as quickly as Mordicai, Rigby, and Pops. Thomas is a goat, so he isn't susceptible to it.
Many were surprised to learn that Margret's father is a human. This actually makes a bit more sense when you watch older episodes, in which, quite a few of Margret's boyfriends were also humans. It doesn't seem weird to her, dating a human.
In "First Day", there's an added scene where Rigby comments that Pops should just throw the chair away. At first this doesn't make a lot of sense, as we soon see he really wants it. Then one remembers that Rigby is a raccoon, and we've seen him pull things out of the trash before back in "Free Cake". He was likely planning to grab it later and get the chair without a fight.
In "More Smarter", Mordecai and Rigby get so intelligent, they start to see their co-workers as more primitive, far less intelligent beings. Muscle Man is reduced to a manatee, which at first seems like a gag on how sloppy his table manners on. But there's a little bit of Fridge Brilliance... Muscle MANatee!
"Steak Me Amadeus" was pretty depressing, what with Mordecai forced to break up with Margaret after she's been accepted into her dream school, strangely enough, he doesn't seem to act all desperate and allows her to go without fuss, why is this? Because the leader of the Capicola Gang, who had formed a pretty ridiculous scheme to get his revenge on the park, derided Margaret's decision seconds before being killed for good this time around. Mordecai must've realized that if Margaret stayed, she could've ended up like the Capicola Gang leader!
Also in the same episode, it makes sense that the Capicola Gang leader sold Pops the fake coupons because Pops is easily gullible and he has never met the Capicola Gang in person so it decreases the chances for the park workers to find out about them.
In Terror Tales Of The Park III, Thomas has to wear his pizza costume until thanksgiving because he told the worst Halloween story. He continues to wear it until The Thanksgiving Special several shows later, when he takes it off. Being that the episodes are usually standalone in some way, this is surprisingly brilliant continuity.
In "The Postcard", when High-Five Ghost and Celia reunite again, why does Celia look exactly the same from four years ago regardless if it's Limited Wardrobe? She wants to make sure that High-Five Ghost will recognize her after all these years so she kept her appearance the same.
After watching Skip Story one realizes why Skip became so obsessed after losing to Rigby (The absolute weakest person in the park), the last time he was weaker Mona died.
In "Benson's Car," the way Jack talks sounds like a stoner. He even has an earring of a green leaf. Seeing that he's from the future, this might mean that marijuana is legalized in the future!
In "Tent Trouble", Mordecai and Rigby have to replace CJ's $200 tent that they accidentally destroyed. While it seems a lot, they should have at least saved up enough money to buy it so why is it difficult for them to afford it? Rigby seems to be the type who would waste money on ridiculous stuff but what about Mordecai? Later in the episode, we see Mordecai with a new smartphone and considering how some of them are expensive, it's no wonder both of them can't afford the tent.
Sure, Mordecai got a do over from Father Time after killing Rigby in "It's Time", but just the fact that the memory of violently killing the person he cares about the most will remain with him for all his life is just... sad; what's even worse is that Rigby will never know that his best friend killed him in an Alternate Universe.
And if that's not enough of a kick in the stomach, thanks to "House Rules", he's trapped with the knowledge that Rigby may die an unavoidable early death...Sweet Dreams, Mordecai.
It's also referenced in "Diary", where Mordecai says "Let's not put anything in the microwave..." after thinking about the first of Rigby's deaths.
Everybody remembers Susan right? Of course you do. Remember her ability to morph her subordinates into her? Well, it's quite possible that the normal looking Susan was somebody else entirely, and that she uses these "clones" to transform as many people as possible so that she may devour most of them, send one (Or maybe even a group.) to get a different job, rinse and repeat.
It didn't make much sense that there were starving dogs in the park in "Death Punchies" after Rigby takes over. Then you realize that Rigby probably killed their owners.
Rigby obsessing over cakes, which he should be allergic to.
After "The Power", there is now a gigantic rampaging monster roaming the surface of the Moon... wait until NASA comes across that!
How will that wizard at the beginning will react when he finds out that someone stole his keyboard...and smashed it?
Rigby getting egged seemed pretty light compared to what happened to the rest of the in his Halloween story, until "Eggscellent" when we find out that Rigby is allergic to eggs. To Rigby, it is really a pretty harsh death.
In "Peeps" Peeps seems to spontaneously generate extra eyes, which doesn't seem like much until you realize he's playing to take everyone eyes. Where do you think he got those other eyes?
In "But I Have a Receipt", after Mordecai stabbed the game store manager in the chest with a ruler, the manager decides to drive home so he can lay down for a minute despite being gravely wounded. In "Exit 9B", among the people who were revived to get revenge on Mordecai and Rigby for killing them is the game store manager. The fact that he was there means that he died along the way when he was driving or at his home.
True, but if the case of the former was happening, Mordecai and Rigby would have inadvertently killed more people because of the manager death potentially causing a traffic accident and not know it; so in some form and fashion, Mordecai and Rigby can come off as a more-or-less Deconstructive Parody of the Karma Houdini pair at their worst.
To be fair, the store manage was trying to kill them first, so he's no more or less deserving of death than their other enemies. Particularly since the portal was apparently to Hell.
In Stick Hockey, Rigby tells Benson the stick hockey game is 'to the death'. Seems like an innocent joke but then you realize: how exactly did Mordecai and Rigby make it to the finals...?
Then again they may have not killed that many people.
While RGB2 was only resting at the end of "That's My Television", the fact that he run out of 80's Air means he's gonna die eventually.
Gets worse when you remember that RGB2 is actually a human being living in a television for a long time, similar to Failure Cresh albeit a character; therefore; is slavery still legal...?!
Possibly. Keep in mind that Mordecai and Rigby were genuinely shocked to find out that he was a human being ad not a sentient TV. It's possible that the TV company have been passing him off as a sentient TV for years, so nobody would know they were violating human rights.
In "Limousine Lunchtime", Skips claims that Mr. Mallard loves his limo almost more than his own son Pops... and at the end after he stains the seat of his recently restored limo, he claims he's so rich he can just buy another limo... does anyone find this messed up?
Stress in the Regular Show world can kill anyone, even immortals.
In Every Meat Burrito, Mordecai, Rigby, Muscle Man and HFG want to eat burritos with meat of every animal. Most likely including birds and raccoons. The ending implies that the Every Meat part is just chicken, but still, Mordecai and Rigby didn't know that. And since it's not confirmed if it was every meat, they could have unknowingly eat another member of their species.
Thomas in a pizza costume in the main continuity. Now the reason why he's forced to wear the costume till Thanksgiving dinner is because he lost in a scary story telling contest, now that "Terror Tales from the Park III" is canon due to Thomas in the pizza costume... THAT MEANS JEBEDIAH TOWNHOUSE IS REAL!
An inconsistency on the writer's part: In "Skips vs. Technology", it is shown that Skips is rather inept when it comes to computers, with no clue whatsoever on how a mouse works, let alone with using computer programs. However, in an earlier episode, ("Over the Top"), when Skips learns about the PlayCo Arm-Boy, he is clearly using the Internet just fine. Considering that the show is rather consistent with minor bits in the series (see "setting up the chairs"), it's surprising that this was missed.
It is possible that "Skips vs. Technology" happened before that episode.
In "The Power", Rigby accidentally sends Skips to the moon by singing, "It's time for you to go to the moon!" Except...he sung that to rhyme with Mordecai's line in the song, which was "It's time for you to go to your room." Since they were both using The Power, why didn't Skips get transported to his room first?
From what I've seen, The Power sees Rigby as the master. That is, while it's happy to follow out an order for Mordecai, it'll follow Rigby's orders if they happen to oppose Mordecai's.
Maybe he went to his room and THEN the moon?
Ever since the "Eggscellent Challenge" Rigby has been shown to eat eggs and egg based products without any ill effects; Rigby is cured of his coma by the trucker's hat, it probably just cured him of his egg allergy!
In "Return of Mordecai and the Rigbys", when all of the park members collapse of heatstroke, instead of calling an ambulance or getting some medical attention, they all get booed and place last.