Question: How come Sadness was the only one who could change the emotion of the memory orb? Don't we sometimes look back at things we thought we were scared of or sad about, and laugh at them? How come the other emotions can't change them the way Sadness can?
Question: At the very ending, now that Dennis is a vampire, can the sun harm him even if he is the son of a human and a vampire?
Question: It is 1968, and in the trailer it says "42 B.G" which 42 years later would be 2010, which is the first film. But the ending of this movie implies that the minions have been working for Gru since he was a child. So why is "42 years Before Gru"?
Chosen answer: The writers wanted to keep Gru's cameo at the end of the film a secret for the fans of the franchise. So, saying "42 Years B.G" (before Gru) in the trailer doesn't give the surprise away.
Question: When Cinderella's stepmother overheard the grand duke telling the captain about his promise to marry off Kit to Princess Shalina, did he (the captain) recognize the stepmother later on when they arrived at her doorstep?
Answer: Even if he did, he didn't know she was the stepmother of Cinderella.
Question: How long were Ben and Audrey dating before the VKs came to Auradon?
Answer: The first Descendants is unclear with this information. SPOILER WARNING. In the beginning of the song "Queen of Mean" from Descendants 3 we see pictures on Audrey's mantle with her and Ben as little kids. So we can assume that they have always had some sort of close relationship, but it still unclear as to when it was official.
Answer: Sadness can change the memories because of Riley's current situation: she has left the home she loved to move to a new city. This makes her happy memories more susceptible to being changed to sad memories. As she remembers things that used to make her happy they now make her sad because she hasn't accepted her new house as home yet. Presumably under the right circumstances the other emotions could do the same thing, just not all the time.