What's So Funny?

There is a whole level of humor I have been unaware of until now - Mathematical jokes.
Person 1: What's the integral of 1/cabin?
Person 2: Log cabin.
Person 1: No, a houseboat – you forgot to add the c!

There are only 10 types of people in the world — those who understand binary, and those who don't.

There are only 10 types of people in the world — those who understand binary, those who don't, and those who understand Gray code.

There are only 10 types of people in the world — those who understand binary, and those who get laid.

There are only 10 types of people in the world — those who understand ternary, those who don't, and those who mistake it for binary.

If only DEAD people understand hexadecimal, how many people understand hexadecimal?

Why do mathematicians think Halloween and Christmas are the same?
Because 31 Oct = 25 Dec.
I wish I were smart enough to not have to look these up to understand why they are funny. The only one I got one I got on my own was:
There are three kinds of people in the world: those who can count, and those who can't.

...It took me a few minutes.