If someone tells you to "go fuck yourself with a knife", you know it's serious.
WTF? Who Said That?Edit
Well that's I.S.T. for you.
So Why the Acronym?Edit
Tfans mod and frequent TFINO poster Hot Rod found the phrase infinitely funny and began to subtly (read: every chance he got) insert it into INH threads in it's acronym form of GFYWAK (pronounced "Jiffy-whack"). Soon anytime anyone wanted to express mock angst or rage, they told someone to GFYWAK. The End.