In the opening scene, Steve talks about inviting his Uncle Cecil to the wedding, but in the "Paris Vacation" episode, he told Stefan that Uncle Cecil was dead.
In this episode, Carl's friend refers to Steve as the kid who blew up the science lab. Carl confirms this, however in the episode "Presumed Urkel", it was found that Steve was framed for the explosion.
In this episode, Steve proposes to Laura in the clothes that he was wearing in the "Marriage 101" episode from season 2 (the one where they were paired together in a class project). He states that he has held onto the ring that he bought her during the project until this day. He originally bought the ring as a gift for her from the "stay away" money his relatives give to him NOT to visit them. Actually, in Marriage 101, Laura says the ring is too much so he sells the ring (and a cd) to Carl to give to Harriette, therefore, he can't possibly give the ring to Laura unless he bought it back from Carl (and we know how Harriette is about rings since she pitched a fit a few episodes before this one because Carl gave her a wedding ring that he had bought for someone else).
While shopping in the mall, Myrtle says to Laura and Maxine that the clothes they are picking out "don't say Myrtle. They say 'Kelly' or 'Cherie' or some cutesy little name like that." Kelly and Cherie are "Laura" and "Maxine's" real-life first names.
How could Steve make it back home from Myra's house without his glasses? In previous episodes, such as "Fast Eddie Winslow" and "Busted," it was established that Steve couldn't see a thing without his glasses on.
After Urkel causes Carl to fall over the kitchen counter, flailing everything all over the place, a yellow bowl settles upside-down in front of a china cabinet. In an immediately subsequent shot, the bowl is gone.
Richie called Mother Winslow "Grandma." She's not his Grandma. She's Eddie and Laura's Grandma because she's Carl's mother. She can't be Richie's Grandma because Richie's mother is Rachel, Harriette's sister.
At the beginning of this episode when Steve tells Laura that he just got a job as a gift wrapper at the mall but when he said it said that he is now a "rapper" and Laura thought he was saying that he is now a singing rapper and she said that he can't even carry a tune. But how could that be when in Episode #74, "Dance to the music" that Steve wrote a rap song for Laura asking her to the Homecoming Dance for the 26th time and the song sounded like Steve carried every single tune of it pretty well.
How did Laura know OGD's real name? He didn't even tell her.
In this episode they make the viewer think that Steve is a bad basketball player but in "Twinkle Toes", Waldo, Steve, and Eddie were in a basketball game and Steve was an excellent player.
This is the first time that Steve Urkel's actor, Jaleel White, talks in his normal voice while wearing the glasses and walking normally.
When Steve is watching TV, he says to himself "let's see what's on ABC." He immediately falls asleep and begins to dream, CBS' way of getting back at ABC for the episode "Life In The Fast Lane" when Steve and Laura fell to sleep watching CBS.
While the lights dimmed when Urkel used his invention, computers somehow stay powered on.
If in episode #37, it says that Eddie was born January 28th, 1974, shouldn't Eddie's birthday already passed and he would be 23 by now?
When Carl and Frank are talking, they say that their Dad died ten years ago, but in the episode "We're Going To Disney World", Mother Winslow says that their father died before Disney World was even built, which was in 1971.
Carl obviously doesn't want to talk to his brother in any way, but in episode 1 he suggests to call Frank to get his mom to stay with him. I guess because it was nine years earlier, and they only hadn't talked to each other for one year at that time, Carl wasn't as angry as he was nine years later.
In the episode when Rachel and Harriette's father returns, Carl says that he bought the red wall unit in the back of the living room. But in this episode the red thing is already there before any of the Winslows stuff is in the house.
Carl says that he bought the house on March 8, 1976. But in episode #37, "Son", it is revealed that Carl and Harriette moved in right before Eddie was born, in 1974.
When they travel back in time to the living room the wallpaper is different and there is carpeting on the floor. In another episode, they flashback to the night Eddie was born in the living room, the night after they moved in. There is no carpeting on the floor and the walls are white.
When Max asks Laura how long they've been friends, Laura says "since third grade." Max replies, "That's right, ever since we came to school with our Punky Brewster lunch boxes," an in-joke about Cherie Johnson starring on Punky Brewster when she was younger.