Shmuck

A: Someone (usually school age) who doesn't care about their future.
B: Someone (usually school age) who doesn't care about their appearance.
C: Someone who doesn't know or disregards common etiquette.
D: Someone who you are better than.

Shmuck: Ya i'm getting all F's this year but I'll just try then get all good grades next year.

Unfortunate Friend: Get your shit together you Shmuck.