Feel free to add more as I love learning shit like this. It's great for small talk and conversation starters.
1. A salute was first introduced in medieval times when knights passing each other would raise their visor to show their face. This was a sign of respect and became military tradition.
2. The term, "Something smells fishy" has actually nothing to do with fish. It's from the Lindbergh baby kidnapping case in the 1930's. The suspect Richard Hauptmann said he received suspicious items in his possession from an associate, Isidor Fisch. Fisch had passed away so the the investigators said his story smelled "Fischy".