Dear WW: During WWII, there were publications STARS AND STR{PES. fpr example. One of them< I can't remember which, had a reqular cartoon feature, SAD SACK, with a real loser, always in trouble from doing
something against regulations, and getting punishment details, policing the area for cigarette butts, etc.
The phrase that inspired it was: "He's a sad sack of shit." Incidentally, there was the word "blivet" which
meant two hundred pounds of shit in a hundred pound sack.