1. Because Mary-Kate and Ashley were losing different teeth at different times, they had to wear fake teeth towards the end of the series to keep up the facade that Michelle Tanner was one person.
2. John Stamos almost had the Olsen twins fired while filming the pilot. He hated how much they cried while filming, but the producers disliked the red-headed twins who replaced them, so they brought back Mary-Kate and Ashley.
3. Originally, Lori Loughlin who played Aunt Becky was only hired on for six episodes.
4. Actor John Posey originally starred as Danny Tanner in an unaired pilot of the show. (And yes, John Posey is the father of Tyler Posey, Scott McCall of MTV's Teen Wolf.)
5. Mary-Kate and Ashley Olsen were credited as "Mary Kate Ashley Olsen" (one person) during the show's intro for several seasons because the producers wanted to hide the fact that the twins were playing the single role.
6. Actress Andrea Barber, better known as ditzy neighbor Kimmy Gibler, originally auditioned for the role of D.J. Tanner.
7. Comet, the Tanner's beloved Golden Retriever, also played the original Buddy in the movie Air Bud.
8. Bob Saget and Dave Coulier were friends long before Full House when they met at a Detroit comedy club. Much like the premise of Full House, Dave Coulier actually stayed on Bob Saget's couch for a few weeks in L.A. when Dave was just 18 years old.
10. The WB almost picked up the show for a ninth season after ABC cancelled it, but the cast decided not to sign on after John Stamos and Candace Cameron announced that Season 8 would be their last.
Step By Step
11. In the first few seasons of the series, during the opening credits, there is an extra, unspecified kid in the Lambert/Foster clan.
12. The show's theme song "Second Time Around" was written and composed by Jesse Frederick and Bennett Salvay, both of whom wrote the themes for other sitcoms including Full House, Perfect Strangers, and Family Matters.
13. In Season 6, Jean-Luc tells Carol that she looks like Chrissy from Three's Company during the episode "Show Me The Money." In case you didn't know, Suzanne Somers actually played Chrissy on Three's Company.
14. In Seasons 1-6, the opening credits spell actress Staci Keanan's name with an i at the end of her name. In Season 7, they changed the spelling of her name to end with a y instead. The reasoning behind this change, or even mistake, has never been explained.
15. The opening of the show is at an amusement park that is supposed to be located on the shores of Lake Michigan. The amusement park is actually Six Flags Magic Mountain, located in Valencia, Calif.
16. Oh, and that ocean splashing against the roller coaster? That's computer animated water to cover up a less-appealing parking lot.
17. Angela Watson, the actress who played the ditzy Karen Foster, created the foundation Child Actors Supporting Themselves (CAST) -- an organization that helps young actors manage their finances -- after learning that her own parents defrauded her out of millions.
18. The show was set in the same television universe as Family Matters. In fact, Steve Urkel appeared in the second episode of the series.
Sabrina, The Teenage Witch
19. Sabrina and her talking cat Salem are the only characters out of the entire series that appeared in all 163 episodes.
20. Sabrina Spellman is actually based on a comic book character from the long-running Archie comics franchise.
21. Although the show is set in fictional Westbridge, Mass., Sabrina's zip code is 01970, the same zip code for Salem, Mass., -- home of the infamous witch trials.
23. Amanda Wiccan, Sabrina's annoying younger cousin, was actually played by Emily Hart, Melissa Joan Hart's real-life sister.
24. Melissa Joan Hart produced Sabrina the Animated Series, the spinoff to the sitcom. She was the voice of Hilda and Zelda.
25. In June 2014, Archie Comics announced the teenage witch was going to have her very own comic series, titled Sabrina.
26. Nick Bakay, the actor who voiced Salem in all seven seasons of the series, has also been a producer on The King of Queens, Two and a Half Men, and most recently, CBS' Mom.
27. Family Matters was actually a spinoff from ABC's Perfect Strangers.
28. Despite Steve Urkel becoming the most iconic character on the show, Urkel was originally only supposed to be a one-episode character.
28. Louis Armstrong's "What a Wonderful World" was the original theme song for the first season.
29. When Jaimee Foxworth, the actress who played Judy Winslow, asked for a raise, producers took her out of the show with no explanation. Foxworth went on to appear in pornographic films under the name "Crave."
30. Jo Marie Peyton, the actress who played Harriette, left halfway through season 9 because of how much the show focused on Urkel.
31. In addition to his cameo on Step By Step, Urkel also made a cameo appearance on Full House.
32. Michelle Thomas, the actress who played Urkel's girlfriend, died shortly after the series ended at the age of 30 after losing a battle to cancer.
Boy Meets World
33. Cory was supposed to have many friends throughout the show as opposed to just having Shawn as a best friend. Shawn's character had only two lines in the original script for the Boy Meets World pilot.
34. Over the course of the series, Topanga's parents were played by five different actors. Talk about family issues.
35. During the show's early years, the set was also a classroom for the child actors to learn in between shoots.
36. Rider Strong, the actor who played Shawn, actually hated his iconic haircut, but producers didn't allow him to touch his hair during the run of the series. When Strong found out the series was cancelled, he finally cut off those brown wavy locks.
37. Parks And Recreation star Adam Scott played a school bully named Griff Hawkins on the second season of the show. (Still hot as ever.)
38. Over the course of the the show, Cory and the gang skipped a total of two school grades.
39. Scenes between Eric and Shawn were limited because they became such good friends over the course of the series that it was hard for them to shoot scenes without constantly laughing at each other.
40. Rider Strong wanted to quit the show to attend college. Producers convinced him to stay on the show as well as take college courses in the morning so he could do both.