Saying or doing something so outdate it's stupid or funny. Often done knowingly to be funny or romantic. It can also be done unknowingly as a result of be uninformed.
"Girl you must be tired because you've been running in my mind all day"
Something presented as fresh or original, but which is actually tired and/or lame. Especially, when its lameness derives from being obvious or done to death.
A concept invented to keep people consuming and creating never ending fads.
A concept to doubt yourself and your place within society so that you have to "tune in" to latest fad or latest social construct to remain relevant. If you feel out of place you can get a mental illness..... and fail to love yourself and try to change your idiosyncrasies.....
What is corny to one is not necessarily corny to another.
P1: I can do the macareena dance move, I think it is cool. I'm happy.
P2: <eye rolling> gawwwd that is soo corny, i'm going to bury my head in embarrassment.
P3: I really think macareena is cool and original, that other guy doesn't love himself or other people that well, he is controlled by other people's approval of him.