"Decimate" can mean "destroying a large proportion of a group" and not just "kill every tenth person in a group", which is falling out of use. (It's still utterly inaccurate to use in a situation where everyone is gone.)
On topic, anytime the myth that "people only use 10% of their brain" comes up, I have to facepalm. It just... urgh.
On topic, anytime the myth that "people only use 10% of their brain" comes up, I have to facepalm. It just... urgh.