This is also the first time that Trixie reveals her crush on Timmy, but it is not referenced in later episodes.
This is the first time in the show that Timmy rejects Trixie Tang (which is obviously ironic compared to how Tootie and Trixie treat him, and even more ironic that Timmy's rejection made Trixie much more interested in him as she leaves many messages on his answering machine).
This is the second time that Timmy is shown with five o'clock shadow, the first time was in "Action Packed".
It is revealed that if there is no love on Earth, Cupid and his cherubs will slowly lose power.
It is also revealed that if Cupid disappears from existence, then love will disappear along with it.
This is the first time that Trixie Tang is shown crying.
Cupid - "You're gonna need lots and lots of love" scene is a parody of a similar scene in The Matrix.
The Supremes - Timmy says "Stop! In the name of love" which is a reference to the group's 1965 song.
Sam Hill - Cupid said what the Sam Hill which is a bad word replacement used to refer Sam Hill who was known to swear a lot.
Butch Hartman - Written on a dog bowl is "Butch", a reference to the show creator.
Berlin Wall - The Girl-in wall is a parody of the Berlin Wall which separated Germany into two pieces. Also when Timmy said "Let's tear down this wall!" it is similar to Ronald Reagan saying "We welcome change and openness; for we believe that freedom and security go together, that the advance of human liberty can only strengthen the cause of world peace.
According to Da Rules, it should have been impossible for Timmy to have wished the girls away because it violates the rule of true love. This may not have applied here due to it being a somewhat indirect violation.
In the scene where the Girl-in wall falls, Mr. Turner appears with blond hair and lavender eyes (as pictured above).
The love arrow Cupid gives Timmy will make whoever it's used on to fall in love with Timmy, but later, Timmy uses it on himself to fall in love with Tootie. In reality, that would mean Timmy would fall in love with himself, not Tootie.
In the song "It's great to be a hairy, smelly guy." If you look closely when Cosmo and Timmy are singing the line "To eat, and burp, and fart, and spit and kill all of your food", you can see their mouths going above their eyes. It is also very noticeable if you have a VCR
Timmy and the other boys at Himmsdale grew facial hair while the wish of a world with no girls was in effect. This is impossible as they are too young to have facial hair.
Timmy's facial hair is gone as soon he is placed into the love ninja costume.
When Mr. and Mrs. Turner kiss, Mrs. Turner does not have any shoes on.
Although this episode was aired on February 14, 2003 in the USA, it was produced in 2002 according to the credits.
Timmy: Cosmo! I wish all the girls were back.
Cosmo: You got it! [pause] What's a girl?
Timmy: Well, they're soft, and cuddly!
[Cosmo 'poofs' a big pink cushion into the room.]
Timmy: No, they're warm and they make you feel nice.
[Cosmo 'poofs' a monster truck into the room.]
Cosmo:[To monster truck] Yay! I'm gonna call you Wanda.
One of Cupids' Cherubs: We're losing all love power, I'm transferring the emergency backup power to your coffee machine.