ITT: Things you thought about Pokemon for a long time that you were wrong about

At some point around Diamond and Pearl, I must have completely forgotten that Crobat existed, because I've associated it as a Gen IV Pokemon for almost 10 years. I never saw any of the anime with Brock's Crobat, and I don't remember seeing it in any game before Gen IV. I think this happened because Cyrus' Crobat is his signature Pokemon and all of the other cross-gen evolutions in Gen IV. If I ever owned one in Johto or Hoenn I've completely forgotten.