Literally the trait that is hardest to find in out modern world. So rare it may be a super power.
"wait, my common sense is tingling..." - Deadpool
The inability to detect a Red flag or multiple if applicable.
person 1 (the victim): Its just that her "crazy to hot scale" is really good, bro!
person 2 (a good friend): I'm pretty sure you have a form of dating common sense deficiency.
A friend who tries to explain to you the strange behavior of the male species especially those particular male species that you have been flirting with and have a crush on. They are very sensible which is annoying and calming at the same time because lets face it-over-thinking stuff is tiresome.
Girlfriend-Queen of common sense.
This is what adults use when they think they are supposedly smart.
I'm giving a word an extra prefix because why the fuck not? It'll make me sound smarter.
"I hate teens who use teen common sense, unlike normal common sense."