Your opinion is wrong, but proving it will take so long and accomplish so little that I'm not going to bother. Usually said with a shrug or to end the conversation.
A: I think the Miami Heat will win the NBA championship this year.
B: Fair nuff <shrug>.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.