Why are orphans always on the toilet?
Because they don't have anyone to give them some toilet paper!
Alright listen up, lil' buddy. So, like, orphans don't have parents, right? And who usually makes sure you got TP when you're doin' your business? Your parents, duh! So the joke is that orphans are stuck on the toilet 'cause nobody's there to hand 'em the TP. Get it now, Einstein?