1. The mystery of mysteries. Somthing so mysterious not even Sherlock could take a crack at it.
2. Also can be used to name an unknown place.
1. John: Who the fuck stole my brownies?
Tyler: I don't know. Wasn't me.
Darryl: It's a mysterymania then..
2. Don: Where you live at?
Jake: In Donora, Pennsylvania
Don: That's a mysterymania to me.