Aha, when I was growing up watching this cartoon, I eventually figured out that they were showing episodes from several different series, all out of order... guess I never saw the
first episode.
My only criticism is that it seems like the narration boxes during the flashback should be written as if Fred is saying them to his kids; for example, at 3:53 of the video, instead of "The group takes a raft out to the pirate ship," something like "'We took a raft out to the pirate ship.'"