We were playing cards with friends last night, the subject of earthquakes somehow came up, which eventually led to someone saying: “Richter? Hell, damn near killed her!”
I guess you had to have been there.
What does Mrs. Claus and the female reindeer do on Xmas eve??
They go into town and blow a few bucks. 
Knock knock.
Who’s there?
Impatient cow.
Impa-
MOO!
This Scottish guy goes on a skiing trip to Canada. After a hard day on the slopes, he retires to a bar at the bottom of the mountain.
After about five or six whiskies, he looks up and notices a stuffed animal on the wall with antlers, so he says to the barman, “What the hell is that?”
The barman says, “It’s a moose.”
The Scottish chap says, “Damn! How big are the cats?”
Joker: Here’s a knock-knock joke - Say knock-knock.
Victim: Knock-knock
Joker: Who’s there?
Victim: …
I heard this told as “interrupting” cow, but it works your way too.
I thought the punchline to that was “I must be the luckiest Muslim in Belfast!”
I’ve gotten a few people this way. After a series of knock-knock jokes:
You: “Wanna hear a <insert group to insult here>* knock knock joke?”
Vic: “Okay”
You: “You start”
Vic: “Knock knock”
You: “Who’s there”
Vic: “Uhhhhh”
My success rate is ~70%
- I use “Newfie”
ETA contribution:
What do you get when you cross 50 female pigs with 50 male deer?
100 sows and bucks!
What do you call an Italian with a rubber toe?
Rob-ER-to
The sign read FOR LEASE.
The tag below read NAVIDAD.
“Just fix the damn thing and leave my personal life out of it, okay?”
…nod to Kip Adotta and “Wet Dream”…
How does a mother know her young son is going to design programming languages one day?
She tells him: “Get me two litres of milk from the store. If they have eggs, get me six”.
The store does have eggs.
Son comes home with six litres of milk.
Speaking of programmers…
Why do programmers confuse Halloween and Christmas?
Because 31 OCT = 25 DEC.
How have I never learned this coincidence before??? Thank you!
(oh, and I chuckled too - funny and educational!)
I don’t get it.
An old programmer joke:
How many programmers does it take to change a light bulb?
It can’t be done, it’s a hardware problem.
31 OCT = the number 31 in octal (base 8) = 25 DEC the number 25 in decimal (base 10)
The value “31” in octal (base 8) is expressed as “25” in decimal (base-10)
31 octal = 3*8 + 1 = 25 decimal
To answer your specific question. It’s on the basis of a Base 8 versus Base 10 system of counting wherein month 10 would be 12 on the base-8 system and 31 would be 25 on the base 8 system as well. Therefore 10-31 = 12-25 when converted over.
To answer your question more specifically, nobody gets it. Nobody. One person, one time, somewhere in history, figured out this useless tidbit of knowledge and shared it with his mathematically inclined friends in the form of a riddle. Then, he had to explain it to them because even they didn’t get the joke until it was laid out to them. After that, the joke went around from group to group as a way to show they were in the know even though not a single person in the history of history could have guessed the punchline, let alone understood this joke, before it was explained to them.
Programming can be really dull and tedious sometimes. In that context it’s funny.
There are some really funny software jokes, but they mostly involve berating users, managers, and Microsoft.