During Gru's flashback in the sequel, we learn that he was a pariah among his classmates and they said that getting near him would give them the "Gruuties". Now, remember that the flashback happened sometime in 1969: When the Red Scare was still happening because of the Cold War between Russia and America; the Red Scare was the fear of Communists (Russian spies) invading the U.S. and Gru had a heavy accent that made everyone know he was originally from Russia. And the parents probably warned their kids about Communists. So, Gru's All of the Other Reindeer childhood also came from the fact that the kids were scared that Gru would "infect them and make than betray their country."
Why did Gru give up on romance just because of that one girl in his childhood? Well, given the fact that his mother wasn't exactly supportive towards his dream of going to the moon, constantly rejecting his attempts to impress him. Then, Gru's first crush coldly rejects his attempt to ask her out...along the other children. Having both your own mother and first crush insensitively and coldly reject you in some way...the emotional scars can do some real damage.
Kristen Wiig voiced both Miss Hattie and Lucy Wilde of the film franchise. Now, why would that be important? To contrast their meetings with Gru and relationship with the girls. Gru clearly feigned interest with Miss Hattie because he needed the girls for his plan and she was a horrible mother figure to the girls. Now, when Lucy first met Gru, there's no pretending, he was himself with her; it's pretty much a given that Lucy becomes the positive, mother figure the girls didn't have with Wiig's first character.
It's pretty hard to notice, but in the first movie we get a brief look at Gru's whole family tree; if one were to look more closely, one of the member's name was "Lucy". A sequel later we are introduced to LUCY Wilde. A small foreshadowing that Lucy of the sequel would enter the Gru Family via by marrying Gru. Now there are two 'Lucy Grus'!
Look at how Gru uses his Freeze Ray and Lucy uses her Flamethrower on each other; so he wouldn't be taken away and Lucy to defend herself. Lucy's Flamethrower represents the Sun and Gru's Freeze Ray represents the moon. Both celestial bodies that are connected to each other, both equals, and are the same, yet opposite. Without one, the other can't exist. A subtle Foreshadowing that Gru and Lucy would marry by the end of the sequel.
Watch closely at them after they land in the water, after the volcano explodes. Gru is in the darkness, like the Moon is; then when Lucy emerges from the water, light surrounds her, almost like how the Sun rises in the morning. Finally, when both just stare at each other, totalling in love, Lucy is in the light and Gru is on the darker side.
Gets even more brilliant when you notice their type of clothing: Gru wears black clothing, the color that the Moon is surrounded by. Lucy's dress is turquoise, a type of blue, which is the usual color that always around the Sun.
Also consider this: Gru's bald head could represent the Moon, while Lucy's red locks could represent the Sun.
Hell! Lucy's name comes from the masculine Latin name, "Lucius", which can translate to: "light", "born at dawn or daylight", "shiny", or "of light complexion".
Each had their own Love Epiphany during their respective time. To explain, Gru has his at night and Lucy's was in the morning.
More brilliance when you realize that in the Red Oni, Blue Oni duo that Gru is the Blue (the Moon) and Lucy is the red (the Sun).
Gru realizes his feelings for Lucy after the latter saved him from his date with the obnoxious Shannon. Why then? Lucy did the thing that he would do if he had his Freeze Ray.
Other reasons that he started to have feelings for her, but didn't want to acknowledge are: First, Lucy Wilde knows how to kick butt and he's impressed by her being as much as a Badass as he is. Second, she's the yin to his yang; they're both so different, yet so similar. And last, but certainly not least, Lucy liked him for who he is; something that his first crush and Shannon obviously didn't.
Look closely at the color of Gru's bowtie, vest and handkerchief at his and Lucy's wedding: Their all turquoise, which is the exact color of Lucy's signature dress.
With the addition of Lucy in Gru's family, Gru now has a family consisting of every hair color. Lucy is a redhead, Margo is a brown-haired brunette, Edith is a blond, and Agnes is a black-haired brunette. All of them aren't blood related to each other, which is the point. The movie's theme or one of the themes is that a family doesn't have to be related by blood to be a family.
Look closely at Lucy's wedding attire: She's wearing a white dress with frills at the bottom and has a crown on her head. Now, remember what the girls wore doing their ballet recital at the end of the first movie? Almost the same thing as Lucy in the sequel. Like daughters, like mother.
Becomes a Crowning Moment of Heartwarming when you notice Agnes' dress at the wedding: unlike her sisters, it has two frills, instead of three. Lucy also only has two frills on her dress. In the most sweetest and subtle ways, Agnes was dressing like her mother.
Why was the jelly Gru made with Dr. Nefario and the Minions so disgusting? Well, consider the fact that the jelly is made of every fruit available; sometimes when you mix two things (i.e. vinegar and oil), they just don't mix together. Another reason is that Gru forgot to remove the seeds in the fruits with them and some of the Minions stomped on the fruit with their dirty and unclean shoes. All of that can lead to very, very badly tasting jelly. Plus, Gru is more of a technology guy, not agricultural.
Plus, all those different flavors are enough to overwhelm one's taste buds.
If it contains every "fruit" it would also include tomatoes. Tomatoes aren't exactly renowned for being in jelly, especially with other fruits (probably for a reason).
Technically they are, we just call tomato jelly 'ketchup'.
Why is Gru so protective of Margo? Aside from being a stereotypical father, Gru actually has a good reason to be this way- Margo, back when she was kidnapped by Vector, nearly fell to her death. Gru barely caught her thanks to the help of the Minions. No one after that experience can come out not wanting to ensure his/her daughter is safe!
The wig store's auto-doors only open when Gru bends lower - because the wig store owner is pretty short, so he probably had to recalibrate the sensors a bit.
Agnes and her apparently random Make Me Wanna Shout ability makes more sense if you remember the first movie, where she holds her breath as a threat and Margo says this happens all the time. Charles Atlas Superpower anyone?
Gru and Lucy have one more thing in common: Their bosses. Overweight men who are in charge of something (Perkins to the Bank of Evil and Silas to the AVL), Jerkasses (although, Silas is on the good side), and constantly underestimate one of the duo (Perkins to Gru and Silas to Lucy). They also cause a Tearjerker to both of them: Perkins informing Gru that he wouldn't send money to him to go to the moon and Silas informing Gru that Lucy was being reassigned to Australia.
When Gru and Lucy escape the flying rocket and into the water, why does it take Lucy a while longer to come out of the water than Gru? If once adds up the weight of the duo and impact from the rocket entering the volcano (which is probably huge), it makes sense. Lucy is much skinnier than the bulky Gru, the impact would have had more effect on her.
Why would Gru send Nefario off with a 21-gun fart gun salute? Well, would he trust the minions with any other kind of gun?
Regarding Antonio, where IS his mother? Look to Gru and Eduardo/El Macho's conversation at the Cinco de Mayo party, while Gru's bummed about Lucy leaving. Eduardo essentially tells Gru that he, too, has suffered a broken heart; there's a high possibility that this woman he loved was Antonio's mother. As to why she would leave, any number of reasons arise.
What happens to Antonio now that his father has gone to jail?
Lucy told Gru that she had used her lipstick taser on a couple of her dates. Might be seen as a Rule of Funny, but what could those dates have done or almost done to Lucy, to make her resort to violence?
Lucy resorts to violence at the drop of a hat. She resorted to violence when Gru's date Shannon was merely being obnoxious.
Actually, Lucy resorted to violence when Shannon began bullying him and was about to humiliate him in public. Prior to that, Lucy was only curious; once the date got verbally abusive and threatened him, she immediately goes for the dart gun. Which, again, brings the question: Just what kind of dates has she been on to make this such a natural reaction for her?
It's a slapstick movie. Gru freezes people in a coffee shop in the first movie. Are we going to intuit that he's suffered some trauma that makes him hate waiting in lines? Lucy wanted to talk to Gru and she realized that he wanted out of the date when Shannon was being an obnoxious jerk, so Lucy fired a dart gun. This is the same woman who knocked Gru out and stuffed him in her trunk for the entire trip to HQ. It's a natural response because that was the quickest way to get rid of the date and she's not exactly in tune with the consequences of her eccentric behavior.
Gru is kidnapped and one point and stuffed in the trunk of a car. The trunk opens later and the underside is shown to have no ventilation holes.