The joke plays off the one we've all heard before, about pigs being released with numbers implying one is "still at large" — the joke being that the Germans are such industrious and efficient engineer-types that even school pranksters still facilitate an efficient clean-up. I thought it was clever!

I'm a german and i didn't get it. Which may in itself be an implicit joke about germans.

I’m not surprised. It's based on stereotypes that an actual German would not be as likely to share. (You may also be less likely to have heard the joke this plays off.)

Not the worst joke, but it presumes a large amount of domain-specific knowledge on the part of the listener.

Really good jokes often do. Generally speaking, the more of a "leap" you have to make to get a joke, the funnier it seems to you (all else being equal). This is a large part of the appeal of "inside jokes" and online meme humor (which are inside jokes for online communities).

A good example that would appeal to some segments of the HN crowd, but leave everyone else baffled:

Some people, when confronted with a problem, think "I know, I'll use the Banach-Tarski theorem."

Joke writers face a trade-off between targeting a very specific audience to exploit this effect, or broadening the appeal of the joke to make it more accessible (i.e., make it less funny for more people). The really great commedians figure out how to have it both ways by finding new spins on universal themes, and taking the entire audience on that "leap" together (good "observational humor" often falls into this category). The less successful ones often fall back on broad humor (large audience, not very surprising) or reference humor (surprising "click" for a small audience, baffling for the rest).

>Some people, when confronted with a problem, think "I know, I'll use the Banach-Tarski theorem."

Fuck. I wanted to ask for an explanation, describing what I thought before, but now I got it. :D Thanks for the joke!

Maybe the goats are just trained to come back to the barn after they hear a bell or something, then?