According to Kevin Smith and Jason Mewes the origin is this: When Jason was younger, about 14, he used the "nee"-expression as a means of countering a statement just made, as in "I'm gonna fuck your mom tonight - nee". The "nee"-expression then grew and grew, but always refering to the canellation of "charge" in a statement. Thus, snoogans means to not do anything. Just the same as Wayne's world's "not!"-expression. Of course the snoogans works excellent as a stand alone-expression, but the "true" ethymology is the one stated above.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failure shower.